How it was found

Summary

During my reconnaissance for your bug bounty program, I discovered an instance of nginx version 1.4.6 running at the IP address https://54.153.101.52. To locate it, I search for IRCCloud-related certificated and found the self-signed certificate for this server (https://censys.io/ipv4/54.153.101.52). This version is in the range of nginx versions affected by the CVE, CVE-2014-0133. There is a known exploit for this CVE. According to MITRE, this "heap-based buffer overflow in the SPDY implementation in nginx 1.3.15 before 1.4.7 and 1.5.x before 1.5.12 allows remote attackers to execute arbitrary code via a crafted request."

{F120380}

However, to succeed, I believe that the exploit requires the ngx_http_spdy_module module (which is not compiled by default) and it requires no --with-debug configure option, if the "spdy" option of the "listen" directive is used in a configuration file. Because I am unable to check the configuration of your server, I wanted to inform you of this outdated version.

Checking for Vulnerability Steps

1. Log into server located at 54.153.101.52
2. Check the nginx configuration file. This should provide you with information as to whether or not it is vulnerable.

Mitigation

Regardless, this is a very outdated version of nginx that should likely be updated to the most recent version if you intend to keep if publicly-exposed. This would correct the vulnerability (if it is vulnerable). Alternatively, if you only want to correct the vulnerability, you can use the patch below:

--- src/http/ngx_http_spdy.c
+++ src/http/ngx_http_spdy.c
@@ -1849,7 +1849,7 @@ static u_char *
 ngx_http_spdy_state_save(ngx_http_spdy_connection_t *sc,
     u_char *pos, u_char *end, ngx_http_spdy_handler_pt handler)
 {
-#if (NGX_DEBUG)
+#if 1
     if (end - pos > NGX_SPDY_STATE_BUFFER_SIZE) {
         ngx_log_error(NGX_LOG_ALERT, sc->connection->log, 0,
                       "spdy state buffer overflow: "

Source: https://nginx.org/download/patch.2014.spdy2.txt

Best, @n0rb3r7