As the holiday season approaches, the security landscape brings a recurring challenge: critical vulnerabilities demanding immediate attention.
Recently, CVE-2024-53677, a critical file-upload vulnerability in Apache Struts2, emerged as a pressing concern for organizations reliant upon the framework. Scoring a 9.5 on the CVSS scale, this vulnerability has the potential to expose systems to file-upload exploits and remote code execution (RCE) under specific conditions.
Since the fix was published on December 11, 2024, data from Maven Central shows the vulnerable components have been downloaded nearly 40,000 times. In fact, vulnerable component versions make up 90.4% of total Struts2 downloads over the past week. The stakes are high, and the time to act is yesterday — if you have not yet started, you are already behind.
Discovered last week, CVE-2024-53677 is a path traversal flaw in the Struts2 file upload mechanism, allowing threat actors to upload files to restricted directories.
Compounding the issue, the vulnerability builds upon similar flaws identified in CVE-2023-50164, suggesting that incomplete patches may have contributed to its emergence.
The complexity of this vulnerability makes remediation challenging. Apache advises fixing it by adopting a new file upload interceptor, namely 'Action File Upload,' and upgrading to Struts 6.4.0 or greater. Consequently, use of the older and now-deprecated 'File Upload Interceptor' is strongly discouraged, as doing so puts your application at risk of exploits.
This solution is not backward-compatible, demanding both major version upgrades and extensive code modifications to achieve full security. These requirements dramatically increase the level of effort needed to remediate and extend the window of exposure.
Three factors make CVE-2024-53677 particularly concerning:
Automation potential: The vulnerability is easily automatable, lowering the barrier for threat actors to launch mass exploitation campaigns.
Widespread targets: Struts2 remains widely adopted in enterprise environments, with hundreds of thousands of systems potentially exposed.
Seasonal timing: The holiday season often brings reduced staffing and slower response times, creating a perfect storm for successful exploitation.
Proof-of-concept (PoC) exploit code is already circulating, and early indicators of active attacks have surfaced. Alerts from organizations such as NIST in the US and NHS in the UK underscore the urgency of applying patches promptly.
Remediation for CVE-2024-53677 is challenging, increasing the risks tied to the vulnerability. Transitioning to a new file upload interceptor extends exposure windows, as it requires both upgrading the component and reworking related code.
If impacted organizations continue to use the old File Upload mechanism, they will continue to be vulnerable. These delays can be catastrophic for organizations unprepared to identify affected systems across the entire organization’s software stack.
Data from our State of the Software Supply Chain highlights a related critical insight: preparedness is the key to resilience. Organizations with strong processes for addressing vulnerabilities outperform their peers in remediation speed. In contrast, unprepared organizations waste time simply identifying vulnerabilities.
To address this vulnerability effectively, organizations should:
Catalog software assets: Maintain an up-to-date software bill of materials (SBOM) to identify dependencies on Struts2.
Scan for vulnerabilities: Use software composition analysis (SCA) tools to pinpoint affected and vulnerable components.
Prioritize patch management: Implement Apache's recommended fixes and transition to the new Action File Upload mechanism as soon as possible.
Monitor exploitation trends: Stay informed on attack campaigns and adjust defensive strategies accordingly.
Prepare for future vulnerabilities: Conduct tabletop exercises to ensure readiness for future incidents.
CVE-2024-53677 serves as a stark reminder of the evolving nature of software supply chain security. While this vulnerability is not yet another Log4Shell, it embodies the same principles: automation potential, widespread impact, and the need for vigilant maintenance.
The lessons of past incidents highlight the importance of preparation and swift action.
For insights into vulnerabilities and best practices in software supply chain management, explore Sonatype's State of the Software Supply Chain.