CVE-2022-41957 is a vulnerability identified in the MuhammaraJS Node.js module, which provides C/C++ bindings for manipulating PDF files using JavaScript in Node.js or Electron environments. MuhammaraJS is used for PDF parsing and modification, and it is a successor to the older hummus package. The vulnerability arises from an unchecked return value leading to a NULL pointer dereference (CWE-690) when processing maliciously crafted PDF files. Specifically, when MuhammaraJS versions prior to 2.6.2 or between 3.0.0 and 3.3.9 parse a specially crafted PDF, the module may attempt to dereference a NULL pointer due to failure in handling certain internal function return values. This results in a Denial of Service (DoS) condition, causing the application or service using MuhammaraJS to crash or become unresponsive. The issue has been addressed in MuhammaraJS version 3.4.0, with the fix backported to version 2.6.2. Users of the predecessor package hummus are advised to migrate to MuhammaraJS to avoid this vulnerability. No known exploits have been reported in the wild to date. The vulnerability does not require authentication or user interaction beyond supplying a malicious PDF file to the vulnerable parser. The root cause is insufficient validation of function return values leading to unsafe memory access in native bindings, a common risk in modules bridging JavaScript and native code.

For European organizations, the primary impact of this vulnerability is the potential for Denial of Service attacks against applications or services that utilize MuhammaraJS or hummus for PDF processing. This can disrupt business operations, especially in sectors heavily reliant on automated PDF handling such as legal, finance, publishing, and government services. The DoS could be triggered remotely by submitting crafted PDF files, potentially via web portals, email attachments, or API endpoints that accept PDFs. While the vulnerability does not lead to code execution or data leakage, the availability impact could be significant if exploited at scale or against critical infrastructure. Organizations processing large volumes of PDFs or integrating MuhammaraJS in backend services may experience service outages or degraded performance. Additionally, the presence of native C/C++ bindings increases the risk of application crashes, which could complicate incident response and recovery. The lack of known exploits reduces immediate risk, but the ease of triggering a crash by supplying a malicious PDF file means attackers with minimal sophistication could cause disruption. European entities with public-facing services that accept PDF uploads are particularly at risk, as attackers could weaponize this vulnerability to cause denial of service without needing authentication or user interaction beyond file submission.

1. Upgrade MuhammaraJS to version 3.4.0 or later, or at minimum to version 2.6.2 where the patch has been backported. 2. Replace any usage of the deprecated hummus package with MuhammaraJS to benefit from maintained security fixes. 3. Implement strict input validation and sanitization on all PDF files before processing, including file type verification and scanning for known malicious patterns. 4. Employ sandboxing or containerization for PDF processing components to isolate potential crashes and prevent service-wide outages. 5. Monitor application logs and crash reports for signs of NULL pointer dereferences or unexpected terminations related to PDF processing. 6. Limit exposure by restricting PDF upload functionality to authenticated and authorized users where possible, reducing attack surface. 7. Use rate limiting and anomaly detection on endpoints accepting PDFs to detect and block suspicious activity indicative of DoS attempts. 8. Maintain an inventory of all applications and services using MuhammaraJS or hummus to ensure timely patching and risk assessment. 9. Consider implementing fallback mechanisms or redundancy for critical PDF processing workflows to maintain availability during incidents.