Greg MacManus, of iSIGHT Partners Labs, found a security problem in several recent versions of nginx. A stack-based buffer overflow might occur in a worker process while handling a specially crafted request, potentially resulting in arbitrary code execution (CVE-2013-2028). The problem affects nginx 1.3.9 - 1.4.0. The problem is fixed in nginx 1.5.0, 1.4.1. Patch for the problem can be found here: http://nginx.org/download/patch.2013.chunked.txt As a temporary workaround the following configuration can be used in each server{} block: if ($http_transfer_encoding ~* chunked) { return 444; } FIX: --- src/http/ngx_http_parse.c +++ src/http/ngx_http_parse.c @@ -2209,6 +2209,10 @@ data: } + if (ctx->size < 0 || ctx->length < 0) { + goto invalid; + } + return rc; done: