CVE-2011-5221 in WebSVN
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in the getLog function in svnlook.php in WebSVN before 2.3.1 allows remote attackers to inject arbitrary web script or HTML via the path parameter to (1) comp.php, (2) diff.php, or (3) revision.php.
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Analysis
by VulDB Data Team • 02/23/2019
The CVE-2011-5221 vulnerability represents a critical cross-site scripting flaw discovered in WebSVN versions prior to 2.3.1, specifically within the getLog function of the svnlook.php component. This vulnerability resides in the web-based version control system interface that allows users to browse and interact with subversion repositories through a web browser. The flaw manifests when the application fails to properly sanitize user input passed through the path parameter in three distinct script files: comp.php, diff.php, and revision.php. The vulnerability classification aligns with CWE-79, which specifically addresses Cross-Site Scripting attacks where untrusted data is improperly incorporated into web pages without adequate validation or encoding.
The technical exploitation of this vulnerability occurs when remote attackers craft malicious input containing script code within the path parameter of the affected URLs. When the WebSVN application processes this input through the getLog function in svnlook.php, it fails to implement proper input sanitization or output encoding mechanisms. The vulnerable code path allows attacker-controlled data to flow directly into the web response without appropriate filtering, enabling the execution of malicious scripts in the context of the victim's browser. This creates a persistent threat vector where attackers can inject arbitrary HTML and JavaScript code that executes in the victim's browser session, potentially leading to session hijacking, credential theft, or redirection to malicious sites.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with the capability to manipulate the WebSVN interface and potentially access sensitive repository information. An attacker could craft malicious URLs that, when visited by other users, would execute scripts that steal session cookies, redirect users to phishing sites, or even modify the displayed repository content to mislead developers about the actual state of the codebase. The vulnerability affects the core functionality of WebSVN's revision history and comparison features, making it particularly dangerous for development teams that rely on these tools for code review and change tracking. The attack surface is broad as it affects multiple entry points through the three different PHP files, increasing the likelihood of successful exploitation.
Security practitioners should implement immediate mitigations including upgrading to WebSVN version 2.3.1 or later, which contains the necessary patches to address the input validation issues. The fix typically involves implementing proper input sanitization techniques and output encoding for all user-supplied parameters before they are processed or displayed in web responses. Organizations should also consider implementing web application firewalls to detect and block suspicious input patterns, while establishing comprehensive input validation policies that align with OWASP Top Ten recommendations. Additionally, regular security assessments of web applications should include testing for XSS vulnerabilities, particularly in components that handle user input through URL parameters. The vulnerability demonstrates the importance of following secure coding practices and proper input validation as outlined in the ATT&CK framework's web application exploitation techniques, where the initial compromise often begins through injection attacks like XSS that can lead to more sophisticated attacks including privilege escalation and data exfiltration.