CVE-2024-46901 in Subversion
Summary
by MITRE • 12/09/2024
Insufficient validation of filenames against control characters in Apache Subversion repositories served via mod_dav_svn allows authenticated users with commit access to commit a corrupted revision, leading to disruption for users of the repository.
All versions of Subversion up to and including Subversion 1.14.4 are affected if serving repositories via mod_dav_svn. Users are recommended to upgrade to version 1.14.5, which fixes this issue.
Repositories served via other access methods are not affected.
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Analysis
by VulDB Data Team • 07/15/2025
The vulnerability described in CVE-2024-46901 represents a critical security flaw in Apache Subversion's mod_dav_svn module that stems from inadequate input validation of filename characters. This issue specifically targets the web-based repository access mechanism that allows HTTP-based interactions with Subversion repositories through the Apache HTTP Server module. The flaw enables authenticated users with commit privileges to introduce corrupted revisions into the repository by exploiting insufficient validation of control characters within filenames. Control characters, which are non-printable ASCII values ranging from 0x00 to 0x1F, can include tabulation, line feeds, carriage returns, and other invisible characters that may disrupt normal repository operations. This vulnerability falls under the CWE-174 category of "Insufficient Validation of Filename for Directory Traversal" and relates to CWE-77 and CWE-20, which address improper input validation and command injection vulnerabilities. The attack vector specifically targets the mod_dav_svn module which serves repositories over HTTP, making it particularly dangerous in web-accessible environments where users may have commit access.
The technical implementation of this vulnerability occurs within the filename validation logic of the mod_dav_svn module where control characters are not properly sanitized or rejected during the commit process. When an authenticated user with commit access creates a revision containing filenames with control characters, these characters are stored in the repository without proper validation, potentially causing downstream processing failures or unexpected behavior in client applications that attempt to access these files. The impact extends beyond simple data corruption as these control characters can interfere with normal repository operations, potentially causing clients to fail when attempting to retrieve or process files with malformed names. The vulnerability specifically affects the HTTP-based repository serving mechanism and does not impact other access methods such as svnserve or file system access, which explains why the fix only applies to the mod_dav_svn module. This selective impact aligns with ATT&CK technique T1078.004 which covers legitimate credentials used for persistence and privilege escalation, as the vulnerability requires legitimate commit access to exploit. The flaw essentially allows for a form of repository corruption that can disrupt normal operations for all users of the affected repository, making it particularly concerning in collaborative development environments where multiple developers rely on shared repositories.
The operational impact of CVE-2024-46901 extends beyond simple repository corruption to encompass broader disruption of development workflows and potential security implications. When corrupted revisions are committed to the repository, they can cause various client applications to fail during checkout, update, or browse operations, leading to productivity losses and potential data access issues. The vulnerability essentially creates a persistent disruption mechanism that can be exploited by any authenticated user with commit privileges, making it particularly dangerous in environments where repository access is not strictly controlled. Organizations using mod_dav_svn for web-based repository access face significant operational risks including potential denial of service conditions, data integrity issues, and the possibility of cascading failures in automated build systems that rely on repository integrity. The vulnerability also poses risks to automated security scanning tools and continuous integration pipelines that may encounter unexpected behavior when processing files with control characters in their names. From a compliance perspective, this vulnerability could potentially violate data integrity requirements in regulated environments where repository consistency is critical for audit trails and change tracking. The remediation process requires immediate upgrading to version 1.14.5 or later, which addresses the validation logic to properly reject filenames containing control characters, thereby preventing the corruption of revisions. Organizations should also implement monitoring for suspicious commit activities and consider implementing additional access controls to limit commit privileges to only essential personnel. The fix demonstrates the importance of proper input validation in web-facing applications and highlights the need for comprehensive security testing of all repository access mechanisms, particularly those that expose repository functionality over network protocols.