diff --git a/src/http/modules/ngx_http_fastcgi_module.c b/src/http/modules/ngx_http_fastcgi_module.c
index 5ae42ef62..23ef2957f 100644
--- a/src/http/modules/ngx_http_fastcgi_module.c
+++ b/src/http/modules/ngx_http_fastcgi_module.c
@@ -1446,10 +1446,10 @@ ngx_http_fastcgi_process_header(ngx_http_request_t *r)
                     h->lowcase_key = h->key.data + h->key.len + 1
                                      + h->value.len + 1;
 
-                    ngx_cpystrn(h->key.data, r->header_name_start,
-                                h->key.len + 1);
-                    ngx_cpystrn(h->value.data, r->header_start,
-                                h->value.len + 1);
+                    ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
+                    h->key.data[h->key.len] = '\0';
+                    ngx_memcpy(h->value.data, r->header_start, h->value.len);
+                    h->value.data[h->value.len] = '\0';
                 }
 
                 h->hash = r->header_hash;
diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index 6bb30db4d..75249b749 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -1278,8 +1278,10 @@ ngx_http_proxy_process_header(ngx_http_request_t *r)
             h->value.data = h->key.data + h->key.len + 1;
             h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
 
-            ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
-            ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
+            ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
+            h->key.data[h->key.len] = '\0';
+            ngx_memcpy(h->value.data, r->header_start, h->value.len);
+            h->value.data[h->value.len] = '\0';
 
             if (h->key.len == r->lowcase_index) {
                 ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
diff --git a/src/http/modules/ngx_http_scgi_module.c b/src/http/modules/ngx_http_scgi_module.c
index 08483cd70..5fb2ac5ae 100644
--- a/src/http/modules/ngx_http_scgi_module.c
+++ b/src/http/modules/ngx_http_scgi_module.c
@@ -894,8 +894,10 @@ ngx_http_scgi_process_header(ngx_http_request_t *r)
             h->value.data = h->key.data + h->key.len + 1;
             h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
 
-            ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
-            ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
+            ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
+            h->key.data[h->key.len] = '\0';
+            ngx_memcpy(h->value.data, r->header_start, h->value.len);
+            h->value.data[h->value.len] = '\0';
 
             if (h->key.len == r->lowcase_index) {
                 ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
diff --git a/src/http/modules/ngx_http_uwsgi_module.c b/src/http/modules/ngx_http_uwsgi_module.c
index 367388e63..fb5ff0d78 100644
--- a/src/http/modules/ngx_http_uwsgi_module.c
+++ b/src/http/modules/ngx_http_uwsgi_module.c
@@ -947,8 +947,10 @@ ngx_http_uwsgi_process_header(ngx_http_request_t *r)
             h->value.data = h->key.data + h->key.len + 1;
             h->lowcase_key = h->key.data + h->key.len + 1 + h->value.len + 1;
 
-            ngx_cpystrn(h->key.data, r->header_name_start, h->key.len + 1);
-            ngx_cpystrn(h->value.data, r->header_start, h->value.len + 1);
+            ngx_memcpy(h->key.data, r->header_name_start, h->key.len);
+            h->key.data[h->key.len] = '\0';
+            ngx_memcpy(h->value.data, r->header_start, h->value.len);
+            h->value.data[h->value.len] = '\0';
 
             if (h->key.len == r->lowcase_index) {
                 ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);
diff --git a/src/http/ngx_http_parse.c b/src/http/ngx_http_parse.c
index 61081a414..420c9275f 100644
--- a/src/http/ngx_http_parse.c
+++ b/src/http/ngx_http_parse.c
@@ -814,6 +814,10 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                     break;
                 }
 
+                if (ch == '\0') {
+                    return NGX_HTTP_PARSE_INVALID_HEADER;
+                }
+
                 r->invalid_header = 1;
 
                 break;
@@ -876,6 +880,10 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                 break;
             }
 
+            if (ch == '\0') {
+                return NGX_HTTP_PARSE_INVALID_HEADER;
+            }
+
             r->invalid_header = 1;
 
             break;
@@ -894,6 +902,8 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                 r->header_start = p;
                 r->header_end = p;
                 goto done;
+            case '\0':
+                return NGX_HTTP_PARSE_INVALID_HEADER;
             default:
                 r->header_start = p;
                 state = sw_value;
@@ -915,6 +925,8 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
             case LF:
                 r->header_end = p;
                 goto done;
+            case '\0':
+                return NGX_HTTP_PARSE_INVALID_HEADER;
             }
             break;
 
@@ -928,6 +940,8 @@ ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b,
                 break;
             case LF:
                 goto done;
+            case '\0':
+                return NGX_HTTP_PARSE_INVALID_HEADER;
             default:
                 state = sw_value;
                 break;