PT-2012-06: Security restrictions bypass in nginx for Windows

Vulnerable software

nginx for Windows
Version: 1.2.0 and earlier, 1.3.0 and earlier

Application link:

Severity level

Severity level: Medium
Impact: Security restrictions bypass
Access Vector: Network exploitable 

CVSS v2:
Base Score: 5.0
Vector: (AV:N/AC:L/Au:N/C:P/I:N/A:N)

CVE: CVE-2011-4963

Software description

nginx [engine x] is a HTTP server, reversed proxy server, and also mail proxy server.

Vulnerability description

The specialists of the Positive Research center have a vulnerability detected "Security restrictions bypass" in nginx for Windows.

The system does not consider that NTFS allows users to address folders with extended syntax attribute, while matching the requested resource URL with locations defined in web server configuration. This allows attackers to bypass access restrictions set for static resources.


location ~/directory/ {
    deny all;

An attacker can bypass this restriction if he/she calls the resource as follows:


How to fix

Update your software up to the latest version

For older versions the following configuration can be used as a workaround:

location ~ "(\.|:\$)" {
    deny all;

Advisory status

15.05.2012 - Vendor is notified
15.05.2012 - Vendor gets vulnerability details
05.06.2012 - Vendor releases fixed version and details
07.06.2012 - Public disclosure


The vulnerability was discovered by Vladimir Kochetkov, Positive Research Center (Positive Technologies Company)


Reports on the vulnerabilities previously discovered by Positive Research: