diff --git a/client/mysql_plugin.c b/client/mysql_plugin.c
index f496db4e72b..d87d4269f89 100644
--- a/client/mysql_plugin.c
+++ b/client/mysql_plugin.c
@@ -569,14 +569,14 @@ static int file_exists(char * filename)
   @retval int error = 1, success = 0
 */
 
-static int search_dir(const char * base_path, const char *tool_name,
+static int search_dir(const char *base_path, const char *tool_name,
                       const char *subdir, char *tool_path)
 {
   char new_path[FN_REFLEN];
   char source_path[FN_REFLEN];
 
-  strcpy(source_path, base_path);
-  strcat(source_path, subdir);
+  safe_strcpy(source_path, sizeof(source_path), base_path);
+  safe_strcat(source_path, sizeof(source_path), subdir);
   fn_format(new_path, tool_name, source_path, "", MY_UNPACK_FILENAME);
   if (file_exists(new_path))
   {
@@ -632,7 +632,7 @@ static int load_plugin_data(char *plugin_name, char *config_file)
   FILE *file_ptr;
   char path[FN_REFLEN];
   char line[1024];
-  char *reason= 0;
+  const char *reason= 0;
   char *res;
   int i= -1;
 
@@ -643,14 +643,14 @@ static int load_plugin_data(char *plugin_name, char *config_file)
   }
   if (!file_exists(opt_plugin_ini))
   {
-    reason= (char *)"File does not exist.";
+    reason= "File does not exist.";
     goto error;
   }
 
   file_ptr= fopen(opt_plugin_ini, "r");
   if (file_ptr == NULL)
   {
-    reason= (char *)"Cannot open file.";
+    reason= "Cannot open file.";
     goto error;
   }
 
@@ -660,17 +660,20 @@ static int load_plugin_data(char *plugin_name, char *config_file)
   /* Read plugin components */
   while (i < 16)
   {
+    size_t line_len;
+
     res= fgets(line, sizeof(line), file_ptr);
+    line_len= strlen(line);
+
     /* strip /n */
-    if (line[strlen(line)-1] == '\n')
-    {
-      line[strlen(line)-1]= '\0';
-    }
+    if (line[line_len - 1] == '\n')
+      line[line_len - 1]= '\0';
+
     if (res == NULL)
     {
       if (i < 1)
       {
-        reason= (char *)"Bad format in plugin configuration file.";
+        reason= "Bad format in plugin configuration file.";
         fclose(file_ptr);
         goto error;        
       }
@@ -683,14 +686,19 @@ static int load_plugin_data(char *plugin_name, char *config_file)
     if (i == -1) /* if first pass, read this line as so_name */
     {
       /* Add proper file extension for soname */
-      strcat(line, FN_SOEXT);
+      if (safe_strcpy(line + line_len - 1, sizeof(line), FN_SOEXT))
+      {
+        reason= "Plugin name too long.";
+        fclose(file_ptr);
+        goto error;
+      }
       /* save so_name */
       plugin_data.so_name= my_strdup(line, MYF(MY_WME|MY_ZEROFILL));
       i++;
     }
     else
     {
-      if (strlen(line) > 0)
+      if (line_len > 0)
       {
         plugin_data.components[i]= my_strdup(line, MYF(MY_WME));
         i++;
@@ -779,14 +787,13 @@ static int check_options(int argc, char **argv, char *operation)
     /* read the plugin config file and check for match against argument */
     else
     {
-      if (strlen(argv[i]) + 4 + 1 > FN_REFLEN)
+      if (safe_strcpy(plugin_name, sizeof(plugin_name), argv[i]) ||
+          safe_strcpy(config_file, sizeof(config_file), argv[i]) ||
+          safe_strcat(config_file, sizeof(config_file), ".ini"))
       {
         fprintf(stderr, "ERROR: argument is too long.\n");
         return 1;
       }
-      strcpy(plugin_name, argv[i]);
-      strcpy(config_file, argv[i]);
-      strcat(config_file, ".ini");
     }
   }
 
@@ -855,35 +862,30 @@ static int check_options(int argc, char **argv, char *operation)
 static int process_options(int argc, char *argv[], char *operation)
 {
   int error= 0;
-  int i= 0;
   
   /* Parse and execute command-line options */
   if ((error= handle_options(&argc, &argv, my_long_options, get_one_option)))
-    goto exit;
+    return error;
 
   /* If the print defaults option used, exit. */
   if (opt_print_defaults)
-  {
-    error= -1;
-    goto exit;
-  }
+    return -1;
 
   /* Add a trailing directory separator if not present */
   if (opt_basedir)
   {
-    i= (int)strlength(opt_basedir);
-    if (opt_basedir[i-1] != FN_LIBCHAR || opt_basedir[i-1] != FN_LIBCHAR2)
+    size_t basedir_len= strlength(opt_basedir);
+    if (opt_basedir[basedir_len - 1] != FN_LIBCHAR ||
+        opt_basedir[basedir_len - 1] != FN_LIBCHAR2)
     {
       char buff[FN_REFLEN];
-      memset(buff, 0, sizeof(buff));
+      if (basedir_len + 2 > FN_REFLEN)
+        return -1;
       
-      strncpy(buff, opt_basedir, sizeof(buff) - 1);
-#ifdef __WIN__
-      strncat(buff, "/", sizeof(buff) - strlen(buff) - 1);
-#else
-      strncat(buff, FN_DIRSEP, sizeof(buff) - strlen(buff) - 1);
-#endif
-      buff[sizeof(buff) - 1]= 0;
+      memcpy(buff, opt_basedir, basedir_len);
+      buff[basedir_len]= '/';
+      buff[basedir_len + 1]= '\0';
+
       my_free(opt_basedir);
       opt_basedir= my_strdup(buff, MYF(MY_FAE));
     }
@@ -895,10 +897,7 @@ static int process_options(int argc, char *argv[], char *operation)
     generated when the defaults were read from the file, exit.
   */
   if (!opt_no_defaults && ((error= get_default_values())))
-  {
-    error= -1;
-    goto exit;
-  }
+    return -1;
 
   /*
    Check to ensure required options are present and validate the operation.
@@ -906,11 +905,9 @@ static int process_options(int argc, char *argv[], char *operation)
    read a configuration file named <plugin_name>.ini from the --plugin-dir
    or --plugin-ini location if the --plugin-ini option presented.
   */
-  strcpy(operation, "");
-  if ((error = check_options(argc, argv, operation)))
-  {
-    goto exit;
-  }
+  operation[0]= '\0';
+  if ((error= check_options(argc, argv, operation)))
+    return error;
 
   if (opt_verbose)
   {
@@ -922,8 +919,7 @@ static int process_options(int argc, char *argv[], char *operation)
       printf("# lc_messages_dir = %s\n", opt_lc_messages_dir);
   }
 
-exit:
-  return error;
+  return 0;
 }
 
 
diff --git a/client/mysqldump.c b/client/mysqldump.c
index 294f29b7acd..b382dd41d08 100644
--- a/client/mysqldump.c
+++ b/client/mysqldump.c
@@ -2478,7 +2478,7 @@ static uint dump_events_for_db(char *db)
   if (mysql_query_with_error_report(mysql, &event_list_res, "show events"))
     DBUG_RETURN(0);
 
-  strcpy(delimiter, ";");
+  safe_strcpy(delimiter, sizeof(delimiter), ";");
   if (mysql_num_rows(event_list_res) > 0)
   {
     if (opt_xml)
diff --git a/client/mysqltest.cc b/client/mysqltest.cc
index 61bb3822d36..e0bd37dd934 100644
--- a/client/mysqltest.cc
+++ b/client/mysqltest.cc
@@ -6171,7 +6171,9 @@ int do_done(struct st_command *command)
     if (*cur_block->delim) 
     {
       /* Restore "old" delimiter after false if block */
-      strcpy (delimiter, cur_block->delim);
+      if (safe_strcpy(delimiter, sizeof(delimiter), cur_block->delim))
+        die("Delimiter too long, truncated");
+
       delimiter_length= strlen(delimiter);
     }
     /* Pop block from stack, goto next line */
@@ -6426,10 +6428,12 @@ void do_block(enum block_cmd cmd, struct st_command* command)
   if (cur_block->ok) 
   {
     cur_block->delim[0]= '\0';
-  } else
+  }
+  else
   {
     /* Remember "old" delimiter if entering a false if block */
-    strcpy (cur_block->delim, delimiter);
+    if (safe_strcpy(cur_block->delim, sizeof(cur_block->delim), delimiter))
+      die("Delimiter too long, truncated");
   }
   
   DBUG_PRINT("info", ("OK: %d", cur_block->ok));
@@ -11301,9 +11305,8 @@ static int setenv(const char *name, const char *value, int overwrite)
   char *envvar= (char *)malloc(buflen);
   if(!envvar)
     return ENOMEM;
-  strcpy(envvar, name);
-  strcat(envvar, "=");
-  strcat(envvar, value);
+
+  snprintf(envvar, buflen, "%s=%s", name, value);
   putenv(envvar);
   return 0;
 }
diff --git a/dbug/dbug.c b/dbug/dbug.c
index 17567585bfd..9c1371730be 100644
--- a/dbug/dbug.c
+++ b/dbug/dbug.c
@@ -508,7 +508,7 @@ static int DbugParse(CODE_STATE *cs, const char *control)
     stack->delay= stack->next->delay;
     stack->maxdepth= stack->next->maxdepth;
     stack->sub_level= stack->next->sub_level;
-    strcpy(stack->name, stack->next->name);
+    safe_strcpy(stack->name, sizeof(stack->name), stack->next->name);
     stack->out_file= stack->next->out_file;
     stack->out_file->used++;
     if (stack->next == &init_settings)
diff --git a/extra/innochecksum.cc b/extra/innochecksum.cc
index 3169b647ea2..a65114a1679 100644
--- a/extra/innochecksum.cc
+++ b/extra/innochecksum.cc
@@ -844,7 +844,7 @@ parse_page(
 {
 	unsigned long long id;
 	uint16_t undo_page_type;
-	char str[20]={'\0'};
+	const char *str;
 	ulint n_recs;
 	uint32_t page_no, left_page_no, right_page_no;
 	ulint data_bytes;
@@ -852,11 +852,7 @@ parse_page(
 	ulint size_range_id;
 
 	/* Check whether page is doublewrite buffer. */
-	if(skip_page) {
-		strcpy(str, "Double_write_buffer");
-	} else {
-		strcpy(str, "-");
-	}
+	str = skip_page ? "Double_write_buffer" : "-";
 
 	switch (mach_read_from_2(page + FIL_PAGE_TYPE)) {
 
diff --git a/extra/mariabackup/xbcloud.cc b/extra/mariabackup/xbcloud.cc
index fed937be834..cee76e5f3d7 100644
--- a/extra/mariabackup/xbcloud.cc
+++ b/extra/mariabackup/xbcloud.cc
@@ -1676,8 +1676,11 @@ container_list_add_object(container_list *list, const char *name,
 		list->object_count += object_count_step;
 	}
 	assert(list->idx <= list->object_count);
-	strcpy(list->objects[list->idx].name, name);
-	strcpy(list->objects[list->idx].hash, hash);
+	safe_strcpy(list->objects[list->idx].name,
+		    sizeof(list->objects[list->idx].name), name);
+	safe_strcpy(list->objects[list->idx].hash,
+		    sizeof(list->objects[list->idx].hash), hash);
+
 	list->objects[list->idx].bytes = bytes;
 	++list->idx;
 }
diff --git a/extra/mariabackup/xtrabackup.cc b/extra/mariabackup/xtrabackup.cc
index f7910fc9c23..ee954919a55 100644
--- a/extra/mariabackup/xtrabackup.cc
+++ b/extra/mariabackup/xtrabackup.cc
@@ -4235,11 +4235,13 @@ static bool xtrabackup_backup_low()
 
 	dst_log_file = NULL;
 
-	if(!xtrabackup_incremental) {
-		strcpy(metadata_type, "full-backuped");
+	if (!xtrabackup_incremental) {
+		safe_strcpy(metadata_type, sizeof(metadata_type),
+			    "full-backuped");
 		metadata_from_lsn = 0;
 	} else {
-		strcpy(metadata_type, "incremental");
+		safe_strcpy(metadata_type, sizeof(metadata_type),
+			    "incremental");
 		metadata_from_lsn = incremental_lsn;
 	}
 	metadata_last_lsn = log_copy_scanned_lsn;
@@ -5987,7 +5989,8 @@ static bool xtrabackup_prepare_func(char** argv)
 	if (ok) {
 		char	filename[FN_REFLEN];
 
-		strcpy(metadata_type, "log-applied");
+		safe_strcpy(metadata_type, sizeof(metadata_type),
+			    "log-applied");
 
 		if(xtrabackup_incremental
 		   && metadata_to_lsn < incremental_to_lsn)
diff --git a/include/m_string.h b/include/m_string.h
index e967f140dc4..8edaf19bc0a 100644
--- a/include/m_string.h
+++ b/include/m_string.h
@@ -225,6 +225,44 @@ static inline void lex_string_set3(LEX_CSTRING *lex_str, const char *c_str,
   lex_str->length= len;
 }
 
+/*
+  Copies src into dst and ensures dst is a NULL terminated C string.
+
+  Returns 1 if the src string was truncated due to too small size of dst.
+  Returns 0 if src completely fit within dst. Pads the remaining dst with '\0'
+
+  Note: dst_size must be > 0
+*/
+static inline int safe_strcpy(char *dst, size_t dst_size, const char *src)
+{
+  memset(dst, '\0', dst_size);
+  strncpy(dst, src, dst_size - 1);
+  /*
+     If the first condition is true, we are guaranteed to have src length
+     >= (dst_size - 1), hence safe to access src[dst_size - 1].
+  */
+  if (dst[dst_size - 2] != '\0' && src[dst_size - 1] != '\0')
+    return 1; /* Truncation of src. */
+  return 0;
+}
+
+/*
+  Appends src to dst and ensures dst is a NULL terminated C string.
+
+  Returns 1 if the src string was truncated due to too small size of dst.
+  Returns 0 if src completely fit within the remaining dst space. Pads the
+            remaining dst with '\0'.
+
+  Note: dst_size must be > 0
+*/
+static inline int safe_strcat(char *dst, size_t dst_size, const char *src)
+{
+  size_t init_len= strlen(dst);
+  if (unlikely(init_len >= dst_size - 1))
+    return 1;
+  return safe_strcpy(dst + init_len, dst_size - init_len, src);
+}
+
 #ifdef __cplusplus
 static inline char *safe_str(char *str)
 { return str ? str : const_cast<char*>(""); }
diff --git a/sql/mysql_install_db.cc b/sql/mysql_install_db.cc
index 9639051e93c..0baaff80ef6 100644
--- a/sql/mysql_install_db.cc
+++ b/sql/mysql_install_db.cc
@@ -243,7 +243,7 @@ static char *get_plugindir()
 {
   static char plugin_dir[2*MAX_PATH];
   get_basedir(plugin_dir, sizeof(plugin_dir), mysqld_path);
-  strcat(plugin_dir, "/" STR(INSTALL_PLUGINDIR));
+  safe_strcat(plugin_dir, sizeof(plugin_dir), "/" STR(INSTALL_PLUGINDIR));
 
   if (access(plugin_dir, 0) == 0)
     return plugin_dir;
diff --git a/sql/mysqld.cc b/sql/mysqld.cc
index e4a814b82dd..ea3849ed9f9 100644
--- a/sql/mysqld.cc
+++ b/sql/mysqld.cc
@@ -5393,12 +5393,11 @@ static int init_server_components()
     else // full wsrep initialization
     {
       // add basedir/bin to PATH to resolve wsrep script names
-      char* const tmp_path= (char*)my_alloca(strlen(mysql_home) +
-                                             strlen("/bin") + 1);
+      size_t tmp_path_size= strlen(mysql_home) + 5; /* including "/bin" */
+      char* const tmp_path= (char*)my_alloca(tmp_path_size);
       if (tmp_path)
       {
-        strcpy(tmp_path, mysql_home);
-        strcat(tmp_path, "/bin");
+        snprintf(tmp_path, tmp_path_size, "%s/bin", mysql_home);
         wsrep_prepend_PATH(tmp_path);
       }
       else
@@ -6254,8 +6253,9 @@ int mysqld_main(int argc, char **argv)
     char real_server_version[2 * SERVER_VERSION_LENGTH + 10];
 
     set_server_version(real_server_version, sizeof(real_server_version));
-    strcat(real_server_version, "' as '");
-    strcat(real_server_version, server_version);
+    safe_strcat(real_server_version, sizeof(real_server_version), "' as '");
+    safe_strcat(real_server_version, sizeof(real_server_version),
+		server_version);
 
     sql_print_information(ER_DEFAULT(ER_STARTUP), my_progname,
                           real_server_version,
@@ -9192,7 +9192,8 @@ static int mysql_init_variables(void)
     }
     else
       my_path(prg_dev, my_progname, "mysql/bin");
-    strcat(prg_dev,"/../");			// Remove 'bin' to get base dir
+    // Remove 'bin' to get base dir
+    safe_strcat(prg_dev, sizeof(prg_dev), "/../");
     cleanup_dirname(mysql_home,prg_dev);
   }
 #else
diff --git a/storage/connect/array.cpp b/storage/connect/array.cpp
index a5c2e065742..1eeb4ac05ca 100644
--- a/storage/connect/array.cpp
+++ b/storage/connect/array.cpp
@@ -975,13 +975,13 @@ PSZ ARRAY::MakeArrayList(PGLOBAL g)
 
   xtrc(1, "Arraylist: len=%d\n", len);
   p = (char *)PlugSubAlloc(g, NULL, len);
-  strcpy(p, "(");
+  safe_strcpy(p, len, "(");
 
   for (i = 0; i < Nval;) {
     Value->SetValue_pvblk(Vblp, i);
     Value->Prints(g, tp, z);
-    strcat(p, tp);
-    strcat(p, (++i == Nval) ? ")" : ",");
+    safe_strcat(p, len, tp);
+    safe_strcat(p, len, (++i == Nval) ? ")" : ",");
   } // enfor i
 
   xtrc(1, "Arraylist: newlen=%d\n", strlen(p));
diff --git a/storage/connect/bson.cpp b/storage/connect/bson.cpp
index 1a1c5cf5d8d..208cd04cb3a 100644
--- a/storage/connect/bson.cpp
+++ b/storage/connect/bson.cpp
@@ -10,6 +10,7 @@
 /*  Include relevant sections of the MariaDB header file.              */
 /***********************************************************************/
 #include <my_global.h>
+#include <m_string.h>
 
 /***********************************************************************/
 /*  Include application header files:                                  */
@@ -598,7 +599,7 @@ PSZ BDOC::Serialize(PGLOBAL g, PBVAL bvp, char* fn, int pretty)
 
   try {
     if (!bvp) {
-      strcpy(g->Message, "Null json tree");
+      safe_strcpy(g->Message, sizeof(g->Message), "Null json tree");
       throw 1;
     } else if (!fn) {
       // Serialize to a string
@@ -606,9 +607,8 @@ PSZ BDOC::Serialize(PGLOBAL g, PBVAL bvp, char* fn, int pretty)
       b = pretty == 1;
     } else {
       if (!(fs = fopen(fn, "wb"))) {
-        snprintf(g->Message, sizeof(g->Message), MSG(OPEN_MODE_ERROR),
-          "w", (int)errno, fn);
-        strcat(strcat(g->Message, ": "), strerror(errno));
+        snprintf(g->Message, sizeof(g->Message), MSG(OPEN_MODE_ERROR) ": %s",
+          "w", (int)errno, fn, strerror(errno));
         throw 2;
       } else if (pretty >= 2) {
         // Serialize to a pretty file
diff --git a/storage/connect/bsonudf.cpp b/storage/connect/bsonudf.cpp
index 2d9132e20ed..8df04232277 100644
--- a/storage/connect/bsonudf.cpp
+++ b/storage/connect/bsonudf.cpp
@@ -4908,7 +4908,7 @@ char *bbin_make_array(UDF_INIT *initid, UDF_ARGS *args, char *result,
 			} // endfor i
 
 			if ((bsp = BbinAlloc(bnx.G, initid->max_length, arp))) {
-				strcat(bsp->Msg, " array");
+				safe_strcat(bsp->Msg, sizeof(bsp->Msg), " array");
 
 				// Keep result of constant function
 				g->Xchk = (initid->const_item) ? bsp : NULL;
@@ -5106,8 +5106,9 @@ char *bbin_array_grp(UDF_INIT *initid, UDF_ARGS *, char *result,
 		PUSH_WARNING("Result truncated to json_grp_size values");
 
 	if (arp)
-		if ((bsp = BbinAlloc(g, initid->max_length, arp)))
-			strcat(bsp->Msg, " array");
+		if ((bsp = BbinAlloc(g, initid->max_length, arp))) {
+                        safe_strcat(bsp->Msg, sizeof(bsp->Msg), " array");
+        }
 
 	if (!bsp) {
 		*res_length = 0;
@@ -5153,8 +5154,9 @@ char *bbin_object_grp(UDF_INIT *initid, UDF_ARGS *, char *result,
 		PUSH_WARNING("Result truncated to json_grp_size values");
 
 	if (bop)
-		if ((bsp = BbinAlloc(g, initid->max_length, bop)))
-			strcat(bsp->Msg, " object");
+		if ((bsp = BbinAlloc(g, initid->max_length, bop))) {
+			safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
+		}
 
 	if (!bsp) {
 		*res_length = 0;
@@ -5198,7 +5200,7 @@ char *bbin_make_object(UDF_INIT *initid, UDF_ARGS *args, char *result,
 					bnx.SetKeyValue(objp, bnx.MakeValue(args, i), bnx.MakeKey(args, i));
 
 				if ((bsp = BbinAlloc(bnx.G, initid->max_length, objp))) {
-					strcat(bsp->Msg, " object");
+					safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
 
 					// Keep result of constant function
 					g->Xchk = (initid->const_item) ? bsp : NULL;
@@ -5253,7 +5255,7 @@ char *bbin_object_nonull(UDF_INIT *initid, UDF_ARGS *args, char *result,
 						bnx.SetKeyValue(objp, jvp, bnx.MakeKey(args, i));
 
 				if ((bsp = BbinAlloc(bnx.G, initid->max_length, objp)))	{
-					strcat(bsp->Msg, " object");
+					safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
 
 					// Keep result of constant function
 					g->Xchk = (initid->const_item) ? bsp : NULL;
@@ -5312,7 +5314,7 @@ char *bbin_object_key(UDF_INIT *initid, UDF_ARGS *args, char *result,
 					bnx.SetKeyValue(objp, bnx.MakeValue(args, i + 1), MakePSZ(g, args, i));
 
 				if ((bsp = BbinAlloc(bnx.G, initid->max_length, objp))) {
-					strcat(bsp->Msg, " object");
+					safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
 
 					// Keep result of constant function
 					g->Xchk = (initid->const_item) ? bsp : NULL;
@@ -6075,7 +6077,7 @@ char *bbin_file(UDF_INIT *initid, UDF_ARGS *args, char *result,
 //		pretty = pty;
 
 	if ((bsp = BbinAlloc(bnx.G, len, jsp))) {
-		strcat(bsp->Msg, " file");
+		safe_strcat(bsp->Msg, sizeof(bsp->Msg), " file");
 		bsp->Filename = fn;
 		bsp->Pretty = pretty;
 	} else {
diff --git a/storage/connect/filamdbf.cpp b/storage/connect/filamdbf.cpp
index a4c2232b1bf..c5694c06b65 100644
--- a/storage/connect/filamdbf.cpp
+++ b/storage/connect/filamdbf.cpp
@@ -442,7 +442,7 @@ PQRYRES DBFColumns(PGLOBAL g, PCSZ dp, PCSZ fn, PTOS topt, bool info)
       hp->Headlen, hp->Filedate[0], hp->Filedate[1],
       hp->Filedate[2]);
 
-    strcat(g->Message, buf);
+    safe_strcat(g->Message, sizeof(g->Message), buf);
     } // endif info
 #endif // 0
 
diff --git a/storage/connect/filamfix.cpp b/storage/connect/filamfix.cpp
index 1df247bd951..d767ba6e4bc 100644
--- a/storage/connect/filamfix.cpp
+++ b/storage/connect/filamfix.cpp
@@ -36,6 +36,8 @@
 #include <fcntl.h>
 #endif  // !_WIN32
 
+#include <m_string.h>
+
 /***********************************************************************/
 /*  Include application header files:                                  */
 /*  global.h    is header containing all global declarations.          */
@@ -883,7 +885,6 @@ bool BGXFAM::OpenTableFile(PGLOBAL g)
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                   FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
                   (LPTSTR)filename, sizeof(filename), NULL);
-    strcat(g->Message, filename);
   } else
     rc = 0;
 
@@ -1004,7 +1005,7 @@ int BGXFAM::Cardinality(PGLOBAL g)
           FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                         FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
                         (LPTSTR)filename, sizeof(filename), NULL);
-          strcat(g->Message, filename);
+          safe_strcat(g->Message, sizeof(g->Message), filename);
           return -1;
         } else
           return 0;                     // File does not exist
@@ -1384,7 +1385,8 @@ bool BGXFAM::OpenTempFile(PGLOBAL g)
   /*********************************************************************/
   tempname = (char*)PlugSubAlloc(g, NULL, _MAX_PATH);
   PlugSetPath(tempname, To_File, Tdbp->GetPath());
-  strcat(PlugRemoveType(tempname, tempname), ".t");
+  PlugRemoveType(tempname, tempname);
+  safe_strcat(tempname, _MAX_PATH, ".t");
   remove(tempname);       // Be sure it does not exist yet
 
 #if defined(_WIN32)
@@ -1393,11 +1395,12 @@ bool BGXFAM::OpenTempFile(PGLOBAL g)
 
   if (Tfile == INVALID_HANDLE_VALUE) {
     DWORD rc = GetLastError();
-    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR), rc, MODE_INSERT, tempname);
+    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR), rc, MODE_INSERT,
+             tempname);
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
               FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
               (LPTSTR)tempname, _MAX_PATH, NULL);
-    strcat(g->Message, tempname);
+    safe_strcat(g->Message, sizeof(g->Message), tempname);
     return true;
     } // endif Tfile
 #else    // UNIX
@@ -1405,8 +1408,8 @@ bool BGXFAM::OpenTempFile(PGLOBAL g)
 
   if (Tfile == INVALID_HANDLE_VALUE) {
     int rc = errno;
-    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR), rc, MODE_INSERT, tempname);
-    strcat(g->Message, strerror(errno));
+    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR)" %s", rc,
+             MODE_INSERT, tempname, strerror(errno));
     return true;
     } //endif Tfile
 #endif   // UNIX
diff --git a/storage/connect/filamgz.cpp b/storage/connect/filamgz.cpp
index 7e9597d6b75..d8ffa63beac 100644
--- a/storage/connect/filamgz.cpp
+++ b/storage/connect/filamgz.cpp
@@ -33,6 +33,8 @@
 #include <fcntl.h>
 #endif  // !_WIN32
 
+#include <m_string.h>
+
 /***********************************************************************/
 /*  Include application header files:                                  */
 /*  global.h    is header containing all global declarations.          */
@@ -128,12 +130,13 @@ int GZFAM::GetFileLength(PGLOBAL g)
 /***********************************************************************/
 bool GZFAM::OpenTableFile(PGLOBAL g)
   {
-  char    opmode[4], filename[_MAX_PATH];
-  MODE    mode = Tdbp->GetMode();
+  const char *opmode;
+  char filename[_MAX_PATH];
+  MODE mode = Tdbp->GetMode();
 
   switch (mode) {
     case MODE_READ:
-      strcpy(opmode, "r");
+      opmode = "rb";
       break;
     case MODE_UPDATE:
       /*****************************************************************/
@@ -147,7 +150,7 @@ bool GZFAM::OpenTableFile(PGLOBAL g)
         DelRows = Cardinality(g);
 
         // This will erase the entire file
-        strcpy(opmode, "w");
+        opmode = "wb";
 //      Block = 0;                // For ZBKFAM
 //      Last = Nrec;              // For ZBKFAM
         Tdbp->ResetSize();
@@ -158,7 +161,7 @@ bool GZFAM::OpenTableFile(PGLOBAL g)
 
       break;
     case MODE_INSERT:
-      strcpy(opmode, "a+");
+      opmode = "a+b";
       break;
     default:
       snprintf(g->Message, sizeof(g->Message), MSG(BAD_OPEN_MODE), mode);
@@ -170,13 +173,11 @@ bool GZFAM::OpenTableFile(PGLOBAL g)
   /*  Use specific zlib functions.                                     */
   /*  Treat files as binary.                                           */
   /*********************************************************************/
-  strcat(opmode, "b");
   Zfile = gzopen(PlugSetPath(filename, To_File, Tdbp->GetPath()), opmode);
 
   if (Zfile == NULL) {
-    snprintf(g->Message, sizeof(g->Message), MSG(GZOPEN_ERROR),
-            opmode, (int)errno, filename);
-    strcat(strcat(g->Message, ": "), strerror(errno));
+    snprintf(g->Message, sizeof(g->Message), MSG(GZOPEN_ERROR) ": %s",
+            opmode, (int)errno, filename, strerror(errno));
     return (mode == MODE_READ && errno == ENOENT)
             ? PushWarning(g, Tdbp) : true;
     } // endif Zfile
diff --git a/storage/connect/filamtxt.cpp b/storage/connect/filamtxt.cpp
index 9ecc2293c48..9db890c5f36 100644
--- a/storage/connect/filamtxt.cpp
+++ b/storage/connect/filamtxt.cpp
@@ -38,6 +38,8 @@
 #include <fcntl.h>
 #endif  // !_WIN32
 
+#include <m_string.h>
+
 /***********************************************************************/
 /*  Include application header files:                                  */
 /*  global.h    is header containing all global declarations.          */
@@ -593,7 +595,7 @@ bool DOSFAM::OpenTableFile(PGLOBAL g)
     } // endswitch Mode
 
   // For blocked I/O or for moving lines, open the table in binary
-  strcat(opmode, (Bin) ? "b" : "t");
+  safe_strcat(opmode, sizeof(opmode), (Bin) ? "b" : "t");
 
   // Now open the file stream
   PlugSetPath(filename, To_File, Tdbp->GetPath());
@@ -1081,7 +1083,8 @@ bool DOSFAM::OpenTempFile(PGLOBAL g)
   /*  Open the temporary file, Spos is at the beginning of file.       */
   /*********************************************************************/
   PlugSetPath(tempname, To_File, Tdbp->GetPath());
-  strcat(PlugRemoveType(tempname, tempname), ".t");
+  PlugRemoveType(tempname, tempname);
+  safe_strcat(tempname, sizeof(tempname), ".t");
 
   if (!(T_Stream = PlugOpenFile(g, tempname, "wb"))) {
     if (trace(1))
@@ -1170,7 +1173,8 @@ int DOSFAM::RenameTempFile(PGLOBAL g)
   
   if (!Abort) {
     PlugSetPath(filename, To_File, Tdbp->GetPath());
-    strcat(PlugRemoveType(filetemp, filename), ".ttt");
+    PlugRemoveType(filetemp, filename);
+    safe_strcat(filetemp, sizeof(filetemp), ".ttt");
     remove(filetemp);   // May still be there from previous error
 
     if (rename(filename, filetemp)) {    // Save file for security
diff --git a/storage/connect/filamvct.cpp b/storage/connect/filamvct.cpp
index f3e31895324..91a6772d961 100644
--- a/storage/connect/filamvct.cpp
+++ b/storage/connect/filamvct.cpp
@@ -42,6 +42,8 @@
 #include <fcntl.h>
 #endif  // !_WIN32
 
+#include <m_string.h>
+
 /***********************************************************************/
 /*  Include application header files:                                  */
 /*  global.h    is header containing all global declarations.          */
@@ -194,7 +196,7 @@ int VCTFAM::GetBlockInfo(PGLOBAL g)
   if (Header == 2)
   {
     PlugRemoveType(filename, filename);
-    strncat(filename, ".blk", _MAX_PATH - strlen(filename));
+    safe_strcat(filename, sizeof(filename), ".blk");
   }
 
   if ((h = global_open(g, MSGID_CANNOT_OPEN, filename, O_RDONLY)) == -1
@@ -251,7 +253,7 @@ bool VCTFAM::SetBlockInfo(PGLOBAL g)
 
   } else {      // Header == 2
     PlugRemoveType(filename, filename);
-    strncat(filename, ".blk", _MAX_PATH - strlen(filename));
+    safe_strcat(filename, sizeof(filename), ".blk");
     s= global_fopen(g, MSGID_CANNOT_OPEN, filename, "wb");
   } // endif Header
 
@@ -586,7 +588,7 @@ bool VCTFAM::InitInsert(PGLOBAL g)
 				htrc("Exception %d: %s\n", n, g->Message);
 			rc = true;
 		} catch (const char *msg) {
-			strncpy(g->Message, msg, sizeof(g->Message));
+			safe_strcpy(g->Message, sizeof(msg), msg);
 			rc = true;
 		} // end catch
 
@@ -890,8 +892,7 @@ bool VCTFAM::OpenTempFile(PGLOBAL g)
   /*********************************************************************/
   PlugSetPath(tempname, To_File, Tdbp->GetPath());
   PlugRemoveType(tempname, tempname);
-  strncat(tempname, ".t", _MAX_PATH - strlen(tempname));
-
+  safe_strcat(tempname, sizeof(tempname), ".t");
   if (MaxBlk) {
     if (MakeEmptyFile(g, tempname))
       return true;
@@ -1562,7 +1563,7 @@ bool VCMFAM::InitInsert(PGLOBAL g)
 		  htrc("Exception %d: %s\n", n, g->Message);
 		rc = true;
   } catch (const char *msg) {
-	  strncpy(g->Message, msg, sizeof(g->Message));
+	  safe_strcpy(g->Message, sizeof(g->Message), msg);
 		rc = true;
   } // end catch
 
@@ -2082,10 +2083,10 @@ bool VECFAM::AllocateBuffer(PGLOBAL g)
       // Allocate all that is needed to move lines and make Temp
       if (UseTemp) {
         Tempat = (char*)PlugSubAlloc(g, NULL, _MAX_PATH);
-        strcpy(Tempat, Colfn);
+        safe_strcpy(Tempat, _MAX_PATH, Colfn);
         PlugSetPath(Tempat, Tempat, Tdbp->GetPath());
         PlugRemoveType(Tempat, Tempat);
-        strncat(Tempat, ".t", _MAX_PATH - strlen(Tempat));
+        safe_strcat(Tempat, _MAX_PATH, ".t");
         T_Fbs = (PFBLOCK *)PlugSubAlloc(g, NULL, Ncol * sizeof(PFBLOCK));
         } // endif UseTemp
 
@@ -2460,7 +2461,7 @@ int VECFAM::RenameTempFile(PGLOBAL g)
       snprintf(filename, _MAX_PATH, Colfn, i+1);
       PlugSetPath(filename, filename, Tdbp->GetPath());
       PlugRemoveType(filetemp, filename);
-      strncat(filetemp, ".ttt", _MAX_PATH - strlen(filetemp));
+      safe_strcat(filetemp, sizeof(filetemp), ".ttt");
       remove(filetemp);   // May still be there from previous error
   
       if (rename(filename, filetemp)) {    // Save file for security
@@ -3221,7 +3222,7 @@ int BGVFAM::GetBlockInfo(PGLOBAL g)
   if (Header == 2)
   {
     PlugRemoveType(filename, filename);
-    strncat(filename, ".blk", _MAX_PATH - strlen(filename));
+    safe_strcat(filename, sizeof(filename), ".blk");
   }
 
 #if defined(_WIN32)
@@ -3300,7 +3301,7 @@ bool BGVFAM::SetBlockInfo(PGLOBAL g)
   } else       // Header == 2
   {
     PlugRemoveType(filename, filename);
-    strncat(filename, ".blk", _MAX_PATH - strlen(filename));
+    safe_strcat(filename, sizeof(filename), ".blk");
   }
 
   if (h == INVALID_HANDLE_VALUE) {
@@ -3398,7 +3399,7 @@ bool BGVFAM::MakeEmptyFile(PGLOBAL g, PCSZ fn)
   FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                 FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
                 (LPTSTR)filename, sizeof(filename), NULL);
-  strncat(g->Message, filename, sizeof(g->Message) - strlen(g->Message));
+  safe_strcat(g->Message, sizeof(g->Message), filename);
 
   if (h != INVALID_HANDLE_VALUE)
     CloseHandle(h);
@@ -3534,7 +3535,7 @@ bool BGVFAM::OpenTableFile(PGLOBAL g)
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
                   FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
                   (LPTSTR)filename, sizeof(filename), NULL);
-    strncat(g->Message, filename, sizeof(g->Message) - strlen(g->Message));
+    safe_strcat(g->Message, sizeof(g->Message), filename);
     } // endif Hfile
 
   if (trace(1))
@@ -3622,8 +3623,8 @@ bool BGVFAM::OpenTableFile(PGLOBAL g)
 
   if (Hfile == INVALID_HANDLE_VALUE) {
     rc = errno;
-    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR), rc, mode, filename);
-    strncat(g->Message, strerror(errno), sizeof(g->Message) - strlen(g->Message));
+    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR)"%s", rc, mode,
+             filename, strerror(errno));
     } // endif Hfile
 
   if (trace(1))
@@ -3967,7 +3968,7 @@ bool BGVFAM::OpenTempFile(PGLOBAL g)
   tempname = (char*)PlugSubAlloc(g, NULL, _MAX_PATH);
   PlugSetPath(tempname, To_File, Tdbp->GetPath());
   PlugRemoveType(tempname, tempname);
-  strncat(tempname, ".t", _MAX_PATH - strlen(tempname));
+  safe_strcat(tempname, _MAX_PATH, ".t");
 
   if (!MaxBlk)
     remove(tempname);       // Be sure it does not exist yet
@@ -3986,7 +3987,7 @@ bool BGVFAM::OpenTempFile(PGLOBAL g)
     FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
               FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
               (LPTSTR)tempname, _MAX_PATH, NULL);
-    strncat(g->Message, tempname, sizeof(g->Message) - strlen(g->Message));
+    safe_strcat(g->Message, sizeof(g->Message), tempname);
     return true;
     } // endif Tfile
 #else    // UNIX
@@ -3996,8 +3997,8 @@ bool BGVFAM::OpenTempFile(PGLOBAL g)
 
   if (Tfile == INVALID_HANDLE_VALUE) {
     int rc = errno;
-    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR), rc, MODE_INSERT, tempname);
-    strncat(g->Message, strerror(errno), sizeof(g->Message) - strlen(g->Message));
+    snprintf(g->Message, sizeof(g->Message), MSG(OPEN_ERROR) "%s", rc, MODE_INSERT,
+             tempname, strerror(errno));
     return true;
     } //endif Tfile
 #endif   // UNIX
diff --git a/storage/connect/filamzip.cpp b/storage/connect/filamzip.cpp
index 814503ae6f7..40926cd2ae7 100644
--- a/storage/connect/filamzip.cpp
+++ b/storage/connect/filamzip.cpp
@@ -29,6 +29,7 @@
 #include <fcntl.h>
 #endif  // !_WIN32
 #include <time.h>
+#include <m_string.h>
 
 /***********************************************************************/
 /*  Include application header files:                                  */
@@ -181,7 +182,8 @@ static bool ZipFiles(PGLOBAL g, ZIPUTIL *zutp, PCSZ pat, char *buf)
 
 	while (true) {
 		if (!(FileData.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) {
-			strcat(strcat(strcpy(filename, drive), direc), FileData.cFileName);
+			snprintf(filename, sizeof(filename), "%s%s%s",
+				 drive, direc, FileData.cFileName);
 
 			if (ZipFile(g, zutp, filename, FileData.cFileName, buf)) {
 				FindClose(hSearch);
@@ -217,7 +219,7 @@ static bool ZipFiles(PGLOBAL g, ZIPUTIL *zutp, PCSZ pat, char *buf)
 	struct dirent *entry;
 
 	_splitpath(filename, NULL, direc, pattern, ftype);
-	strcat(pattern, ftype);
+	safe_strcat(pattern, sizeof(pattern), ftype);
 
 	// Start searching files in the target directory.
 	if (!(dir = opendir(direc))) {
@@ -226,7 +228,7 @@ static bool ZipFiles(PGLOBAL g, ZIPUTIL *zutp, PCSZ pat, char *buf)
 	} // endif dir
 
 	while ((entry = readdir(dir))) {
-		strcat(strcpy(fn, direc), entry->d_name);
+		snprintf(fn, sizeof(fn), "%s%s", direc, entry->d_name);
 
 		if (lstat(fn, &fileinfo) < 0) {
 			snprintf(g->Message, sizeof(g->Message), "%s: %s", fn, strerror(errno));
@@ -240,7 +242,7 @@ static bool ZipFiles(PGLOBAL g, ZIPUTIL *zutp, PCSZ pat, char *buf)
 		if (fnmatch(pattern, entry->d_name, 0))
 			continue;      // Not a match
 
-		strcat(strcpy(filename, direc), entry->d_name);
+		snprintf(filename, sizeof(filename), "%s%s", direc, entry->d_name);
 
 		if (ZipFile(g, zutp, filename, entry->d_name, buf)) {
 			closedir(dir);
diff --git a/storage/connect/javaconn.cpp b/storage/connect/javaconn.cpp
index 0dc467aa7ee..3d1dfbc3f26 100644
--- a/storage/connect/javaconn.cpp
+++ b/storage/connect/javaconn.cpp
@@ -33,6 +33,8 @@
 #define NODW
 #endif  // !_WIN32
 
+#include <m_string.h>
+
 /***********************************************************************/
 /*  Required objects includes.                                         */
 /***********************************************************************/
@@ -231,15 +233,16 @@ bool JAVAConn::GetJVM(PGLOBAL g)
 #if defined(_WIN32)
 		for (ntry = 0; !LibJvm && ntry < 3; ntry++) {
 			if (!ntry && JvmPath) {
-				strcat(strcpy(soname, JvmPath), "\\jvm.dll");
+				snprintf(soname, sizeof(soname), "%s\\jvm.dll", JvmPath);
+
 				ntry = 3;		 // No other try
 			} else if (ntry < 2 && getenv("JAVA_HOME")) {
-				strcpy(soname, getenv("JAVA_HOME"));
+				safe_strcpy(soname, sizeof(soname), getenv("JAVA_HOME"));
 
 				if (ntry == 1)
-					strcat(soname, "\\jre");
+					safe_strcat(soname, sizeof(soname), "\\jre");
 
-				strcat(soname, "\\bin\\client\\jvm.dll");
+				safe_strcat(soname, sizeof(soname), "\\bin\\client\\jvm.dll");
 			} else {
 				// Try to find it through the registry
 				char version[16];
@@ -247,11 +250,12 @@ bool JAVAConn::GetJVM(PGLOBAL g)
 				LONG  rc;
 				DWORD BufferSize = 16;
 
-				strcpy(soname, "jvm.dll");		// In case it fails
+				safe_strcpy(soname, sizeof(soname), "jvm.dll");		// In case it fails
 
 				if ((rc = RegGetValue(HKEY_LOCAL_MACHINE, javaKey, "CurrentVersion",
 					RRF_RT_ANY, NULL, (PVOID)&version, &BufferSize)) == ERROR_SUCCESS) {
-					strcat(strcat(javaKey, "\\"), version);
+					safe_strcat(javaKey, sizeof(javaKey), "\\");
+					safe_strcat(javaKey, sizeof(javaKey), version);
 					BufferSize = sizeof(soname);
 
 					if ((rc = RegGetValue(HKEY_LOCAL_MACHINE, javaKey, "RuntimeLib",
@@ -272,11 +276,11 @@ bool JAVAConn::GetJVM(PGLOBAL g)
 			char  buf[256];
 			DWORD rc = GetLastError();
 
-			snprintf(g->Message, sizeof(g->Message), MSG(DLL_LOAD_ERROR), rc, soname);
 			FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
 										FORMAT_MESSAGE_IGNORE_INSERTS, NULL, rc, 0,
 				            (LPTSTR)buf, sizeof(buf), NULL);
-			strcat(strcat(g->Message, ": "), buf);
+			snprintf(g->Message, sizeof(g->Message), MSG(DLL_LOAD_ERROR)": %s", rc,
+							 soname, buf);
 		} else if (!(CreateJavaVM = (CRTJVM)GetProcAddress((HINSTANCE)LibJvm,
 			                                       "JNI_CreateJavaVM"))) {
 			snprintf(g->Message, sizeof(g->Message), MSG(PROCADD_ERROR), GetLastError(), "JNI_CreateJavaVM");
@@ -301,13 +305,14 @@ bool JAVAConn::GetJVM(PGLOBAL g)
 
 		for (ntry = 0; !LibJvm && ntry < 2; ntry++) {
 			if (!ntry && JvmPath) {
-				strcat(strcpy(soname, JvmPath), "/libjvm.so");
+				snprintf(soname, sizeof(soname), "%s/libjvm.so", JvmPath);
 				ntry = 2;
 			} else if (!ntry && getenv("JAVA_HOME")) {
 				// TODO: Replace i386 by a better guess
-				strcat(strcpy(soname, getenv("JAVA_HOME")), "/jre/lib/i386/client/libjvm.so");
+				snprintf(soname, sizeof(soname), "%s/jre/lib/i386/client/libjvm.so",
+								 getenv("JAVA_HOME"));
 			} else {	 // Will need LD_LIBRARY_PATH to be set
-				strcpy(soname, "libjvm.so");
+				safe_strcpy(soname, sizeof(soname), "libjvm.so");
 				ntry = 2;
 			} // endelse
 
diff --git a/storage/connect/json.cpp b/storage/connect/json.cpp
index 0786c3139e1..9cce77d025a 100644
--- a/storage/connect/json.cpp
+++ b/storage/connect/json.cpp
@@ -10,6 +10,7 @@
 /*  Include relevant sections of the MariaDB header file.              */
 /***********************************************************************/
 #include <my_global.h>
+#include <m_string.h>
 
 /***********************************************************************/
 /*  Include application header files:                                  */
@@ -270,7 +271,7 @@ PSZ Serialize(PGLOBAL g, PJSON jsp, char* fn, int pretty) {
     jdp->dfp = GetDefaultPrec();
 
     if (!jsp) {
-      strcpy(g->Message, "Null json tree");
+      safe_strcpy(g->Message, sizeof(g->Message), "Null json tree");
       throw 1;
     } else if (!fn) {
       // Serialize to a string
@@ -278,9 +279,8 @@ PSZ Serialize(PGLOBAL g, PJSON jsp, char* fn, int pretty) {
       b = pretty == 1;
     } else {
       if (!(fs = fopen(fn, "wb"))) {
-        snprintf(g->Message, sizeof(g->Message), MSG(OPEN_MODE_ERROR),
-          "w", (int)errno, fn);
-        strcat(strcat(g->Message, ": "), strerror(errno));
+        snprintf(g->Message, sizeof(g->Message), MSG(OPEN_MODE_ERROR) ": %s",
+                 "w", (int)errno, fn, strerror(errno));
         throw 2;
       } else if (pretty >= 2) {
         // Serialize to a pretty file
diff --git a/storage/connect/jsonudf.cpp b/storage/connect/jsonudf.cpp
index 1b5ff9ae0c4..d48489298ac 100644
--- a/storage/connect/jsonudf.cpp
+++ b/storage/connect/jsonudf.cpp
@@ -4753,7 +4753,7 @@ char *jbin_array(UDF_INIT *initid, UDF_ARGS *args, char *result,
 
 			if ((arp = (PJAR)JsonNew(g, TYPE_JAR)) &&
 					(bsp = JbinAlloc(g, args, initid->max_length, arp))) {
-				strcat(bsp->Msg, " array");
+				safe_strcat(bsp->Msg, sizeof(bsp->Msg), " array");
 
 				for (uint i = 0; i < args->arg_count; i++)
 					arp->AddArrayValue(g, MakeValue(g, args, i));
@@ -4830,7 +4830,7 @@ char *jbin_array_add_values(UDF_INIT *initid, UDF_ARGS *args, char *result,
 			arp->InitArray(gb);
 
 			if ((bsp = JbinAlloc(g, args, initid->max_length, top))) {
-				strcat(bsp->Msg, " array");
+				safe_strcat(bsp->Msg, sizeof(bsp->Msg), " array");
 				bsp->Jsp = arp;
 			}	// endif bsp
 
@@ -5051,7 +5051,7 @@ char *jbin_object(UDF_INIT *initid, UDF_ARGS *args, char *result,
 
 
 				if ((bsp = JbinAlloc(g, args, initid->max_length, objp)))
-					strcat(bsp->Msg, " object");
+					safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
 
 			} else
 				bsp = NULL;
@@ -5107,7 +5107,7 @@ char *jbin_object_nonull(UDF_INIT *initid, UDF_ARGS *args, char *result,
 						objp->SetKeyValue(g, jvp, MakeKey(g, args, i));
 
 				if ((bsp = JbinAlloc(g, args, initid->max_length, objp)))
-					strcat(bsp->Msg, " object");
+					safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
 
 			} else
 				bsp = NULL;
@@ -5166,7 +5166,7 @@ char *jbin_object_key(UDF_INIT *initid, UDF_ARGS *args, char *result,
 					objp->SetKeyValue(g, MakeValue(g, args, i + 1), MakePSZ(g, args, i));
 
 				if ((bsp = JbinAlloc(g, args, initid->max_length, objp)))
-					strcat(bsp->Msg, " object");
+					safe_strcat(bsp->Msg, sizeof(bsp->Msg), " object");
 
 			} else
 				bsp = NULL;
@@ -5388,7 +5388,7 @@ char *jbin_object_list(UDF_INIT *initid, UDF_ARGS *args, char *result,
 		} // endif CheckMemory
 
 		if ((bsp = JbinAlloc(g, args, initid->max_length, jarp)))
-			strcat(bsp->Msg, " array");
+			safe_strcat(bsp->Msg, sizeof(bsp->Msg), " array");
 
 		// Keep result of constant function
 		g->Xchk = (initid->const_item) ? bsp : NULL;
@@ -5463,7 +5463,7 @@ char *jbin_get_item(UDF_INIT *initid, UDF_ARGS *args, char *result,
 		jsp = (jvp->GetJsp()) ? jvp->GetJsp() : JvalNew(g, TYPE_JVAL, jvp->GetValue(g));
 
 		if ((bsp = JbinAlloc(g, args, initid->max_length, jsp)))
-			strcat(bsp->Msg, " item");
+			safe_strcat(bsp->Msg, sizeof(bsp->Msg), " item");
 		else
 			*error = 1;
 
@@ -5823,7 +5823,7 @@ char *jbin_file(UDF_INIT *initid, UDF_ARGS *args, char *result,
 		pretty = pty;
 
 	if ((bsp = JbinAlloc(g, args, len, jsp))) {
-		strcat(bsp->Msg, " file");
+		safe_strcat(bsp->Msg, sizeof(bsp->Msg), " file");
 		bsp->Filename = fn;
 		bsp->Pretty = pretty;
 	} else {
@@ -6159,9 +6159,8 @@ char* JUP::UnprettyJsonFile(PGLOBAL g, char *fn, char *outfn, int lrecl) {
 	/*  Parse the json file and allocate its tree structure.                         */
 	/*********************************************************************************/
 	if (!(fs = fopen(outfn, "wb"))) {
-		snprintf(g->Message, sizeof(g->Message), MSG(OPEN_MODE_ERROR),
-			"w", (int)errno, outfn);
-		strcat(strcat(g->Message, ": "), strerror(errno));
+		snprintf(g->Message, sizeof(g->Message), MSG(OPEN_MODE_ERROR)": %s",
+			"w", (int)errno, outfn, strerror(errno));
 		CloseMemMap(mm.memory, len);
 		return NULL;
 	} // endif fs
diff --git a/storage/connect/myconn.cpp b/storage/connect/myconn.cpp
index e5ea1ac52ae..7a4c2f897a0 100644
--- a/storage/connect/myconn.cpp
+++ b/storage/connect/myconn.cpp
@@ -405,18 +405,20 @@ PQRYRES SrcColumns(PGLOBAL g, const char *host, const char *db,
     port = mysqld_port;
 
 	if (!strnicmp(srcdef, "select ", 7) || strstr(srcdef, "%s")) {
-		query = (char *)PlugSubAlloc(g, NULL, strlen(srcdef) + 10);
+		size_t query_sz = strlen(srcdef) + 10;
+		query = (char *)PlugSubAlloc(g, NULL, query_sz);
 
 		if ((p= strstr(srcdef, "%s")))
 		{
 			/* Replace %s with 1=1 */
-			sprintf(query, "%.*s1=1%s", (int) (p - srcdef), srcdef, p + 2); // dummy where clause
+			snprintf(query, query_sz, "%.*s1=1%s",
+			         (int) (p - srcdef), srcdef, p + 2); // dummy where clause
 		}
-		else 
-		  strcpy(query, srcdef);
+		else
+			safe_strcpy(query, query_sz, srcdef);
 
 		if (!strnicmp(srcdef, "select ", 7))
-		  strcat(query, " LIMIT 0");
+			safe_strcat(query, query_sz, " LIMIT 0");
 
 	} else
     query = (char *)srcdef;