CVE-2010-5293 in WordPress
Summary
by MITRE
wp-includes/comment.php in WordPress before 3.0.2 does not properly whitelist trackbacks and pingbacks in the blogroll, which allows remote attackers to bypass intended spam restrictions via a crafted URL, as demonstrated by a URL that triggers a substring match.
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Analysis
by VulDB Data Team • 01/31/2022
The vulnerability described in CVE-2010-5293 represents a significant security flaw in WordPress core functionality that affected versions prior to 3.0.2. This issue resides within the wp-includes/comment.php file and specifically targets the handling of trackbacks and pingbacks within the blogroll feature. The vulnerability stems from inadequate input validation and sanitization mechanisms that fail to properly whitelist or validate external URLs submitted through these communication channels. Attackers can exploit this weakness by crafting malicious URLs that bypass the intended spam protection measures, potentially allowing unwanted content to be displayed in the blogroll section. The flaw operates through a substring matching technique that enables attackers to circumvent the whitelist validation process, effectively undermining the security controls designed to prevent spam and malicious link insertion.
The technical nature of this vulnerability aligns with CWE-20, which describes improper input validation, and represents a classic case of insufficient sanitization of user-supplied data. The flaw demonstrates how weak validation controls can be exploited to bypass security mechanisms that are fundamental to content management systems. When WordPress processes trackbacks and pingbacks, it should validate the URLs against a strict whitelist of approved domains or patterns to prevent malicious content injection. However, the implementation in affected versions failed to properly enforce these validation rules, creating an avenue for attackers to inject unwanted URLs that would otherwise be rejected by the system's spam filtering mechanisms.
The operational impact of this vulnerability extends beyond simple spam injection, as it can enable more sophisticated attacks including cross-site scripting exploitation and malicious link redirection. Attackers can leverage this weakness to inject harmful URLs that point to malicious domains, potentially leading to phishing attacks or malware distribution through the blogroll section. The vulnerability affects the integrity of the WordPress installation by allowing unauthorized modification of the blogroll content, which can compromise the trust that users place in the website's content. This issue particularly impacts blogs and websites that rely heavily on trackbacks and pingbacks for community engagement, as these features become potential attack vectors for malicious actors.
Mitigation strategies for CVE-2010-5293 focus on immediate patching of affected WordPress installations to version 3.0.2 or later, where the vulnerability has been addressed through improved input validation and sanitization. System administrators should implement additional monitoring of trackback and pingback processing to detect anomalous URL patterns that might indicate exploitation attempts. The recommended approach includes configuring strict whitelist policies for external URLs and implementing rate limiting for trackback requests to prevent abuse. Organizations should also consider implementing web application firewalls that can detect and block suspicious URL patterns targeting this specific vulnerability. The fix implemented in WordPress 3.0.2 demonstrates proper input validation techniques that align with security best practices recommended in the OWASP Top Ten and other industry standards for preventing injection attacks and maintaining application integrity.