CVE-2012-2403 in WordPress
Summary
by MITRE
wp-includes/formatting.php in WordPress before 3.3.2 attempts to enable clickable links inside attributes, which makes it easier for remote attackers to conduct cross-site scripting (XSS) attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 12/23/2024
The vulnerability identified as CVE-2012-2403 resides within the WordPress content management system's core functionality, specifically in the wp-includes/formatting.php file. This flaw represents a classic cross-site scripting vulnerability that emerged in WordPress versions prior to 3.3.2, where the system's attempt to process clickable links within HTML attributes created an exploitable condition. The vulnerability stems from insufficient input validation and sanitization mechanisms that fail to properly handle malformed or maliciously crafted HTML content containing links within attribute values.
The technical implementation of this vulnerability involves the WordPress system's approach to converting plain text URLs into clickable hyperlinks while processing user-generated content. When the system encounters URLs embedded within HTML attributes, it applies linkification logic that does not adequately sanitize the attribute values, allowing malicious payload injection. This occurs because the formatting functions do not properly distinguish between legitimate attribute content and potentially harmful script code that could be embedded within attribute values. The flaw specifically manifests when the system attempts to process links that appear within HTML attributes such as href, src, or other attribute fields, creating an environment where attacker-controlled data can be executed in the context of a user's browser session.
From an operational perspective, this vulnerability enables remote attackers to execute malicious scripts in the context of a victim's browser session, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim. The impact extends beyond simple XSS exploitation as it can be leveraged to bypass certain security controls and establish persistent access to affected systems. Attackers can craft malicious posts, comments, or other user-generated content that, when processed by the vulnerable WordPress installation, executes arbitrary JavaScript code in the browsers of visitors. This vulnerability particularly affects WordPress installations that allow user-generated content or have plugins that process HTML attributes, making it a significant concern for web applications relying on WordPress as their foundation.
The vulnerability aligns with CWE-79, which defines Cross-Site Scripting as a weakness where a web application fails to properly validate or escape user-provided data before including it in dynamically generated web pages. Additionally, this flaw corresponds to ATT&CK technique T1059.007, which involves the use of scripting languages for execution, as attackers can leverage the XSS vulnerability to inject malicious scripts that execute within user browsers. The vulnerability also demonstrates characteristics of T1566, which encompasses social engineering techniques that involve manipulating users into executing malicious code, as the exploitation typically occurs through content that appears legitimate to end users. Organizations should implement comprehensive security measures including regular updates, input validation, and output encoding to prevent exploitation of this vulnerability.
Mitigation strategies for CVE-2012-2403 primarily involve upgrading to WordPress version 3.3.2 or later, where the vulnerability has been addressed through improved input sanitization and attribute handling. System administrators should also implement proper content filtering mechanisms that validate and sanitize all user-generated content before processing, particularly focusing on HTML attribute validation. Additional protective measures include implementing content security policies, using web application firewalls to detect and block malicious payloads, and conducting regular security assessments to identify potential injection points within the application. Organizations should also consider implementing automatic update mechanisms for WordPress core and plugin components to ensure timely patch deployment and reduce exposure windows. The remediation process should include thorough testing of the updated system to ensure that legitimate functionality remains intact while eliminating the XSS vulnerability.