PHP 5.3.x < 5.3.21 cURL X.509 Certificate Domain Name Matching MiTM Weakness

medium Nessus Plugin ID 63621


The remote web server uses a version of PHP that is potentially vulnerable to man-in-the-middle attacks.


According to its banner, the version of PHP 5.3.x installed on the remote host is prior to 5.3.21. It is, therefore, potentially affected by a weakness in the cURL extension that can allow SSL spoofing and man-in-the-middle attacks.

When attempting to validate a certificate, the cURL library (libcurl) fails to verify that a server hostname matches a domain name in an X.509 certificate's 'Subject Common Name' (CN) or 'SubjectAltName'.

Note that this plugin does not attempt to verify whether the PHP install has been built with the cURL extention, but instead relies only on PHP's self-reported version number.


Upgrade to PHP version 5.3.21 or later.

See Also

Plugin Details

Severity: Medium

ID: 63621

File Name: php_5_3_21.nasl

Version: 1.6

Type: remote

Family: CGI abuses

Published: 1/18/2013

Updated: 4/11/2022

Configuration: Enable paranoid mode, Enable thorough checks

Risk Information


Risk Factor: Medium

Base Score: 4.3

Vector: CVSS2#AV:N/AC:M/Au:N/C:N/I:P/A:N

Vulnerability Information

CPE: cpe:/a:php:php

Required KB Items: www/PHP, Settings/ParanoidReport

Patch Publication Date: 1/17/2013

Vulnerability Publication Date: 1/17/2013