CVE-2022-31129 is a vulnerability identified in the moment.js JavaScript library, which is widely used for parsing, validating, manipulating, and formatting dates. The vulnerability stems from an inefficient parsing algorithm used specifically in the string-to-date parsing functionality, with a focus on the default rfc2822 date format parsing. The algorithm exhibits quadratic time complexity (O(N^2)) when processing certain crafted inputs, particularly those exceeding 10,000 characters in length. This inefficiency can be exploited by an attacker to cause uncontrolled resource consumption, leading to a Denial of Service (DoS) or more specifically a ReDoS (Regular Expression Denial of Service) attack. The vulnerability affects moment.js versions from 2.18.0 up to but not including 2.29.4. The issue is due to the lack of input length validation or sanitization before parsing, allowing maliciously long strings to trigger excessive CPU usage. The vulnerability has been patched in version 2.29.4, and the fix can be backported with minimal effort. Users who cannot upgrade are advised to implement input length restrictions to mitigate the risk. No known exploits have been reported in the wild to date, but the potential for exploitation exists given the nature of the vulnerability and the widespread use of moment.js in web applications and services.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on moment.js in web applications, backend services, or client-side scripts that process user-supplied date strings. Exploitation could lead to service degradation or outages due to high CPU consumption, affecting availability and potentially causing denial of service for legitimate users. This can disrupt business operations, degrade user experience, and increase operational costs due to incident response and mitigation efforts. Sectors with high reliance on web services, such as finance, e-commerce, healthcare, and public administration, are particularly vulnerable. Additionally, organizations processing large volumes of user input or integrating third-party services that use moment.js may be indirectly affected. While confidentiality and integrity impacts are minimal, the availability impact is moderate to high depending on the deployment context. The absence of authentication or user interaction requirements for triggering the vulnerability increases the risk, as attackers can exploit it remotely by submitting crafted inputs.

1. Upgrade all instances of moment.js to version 2.29.4 or later immediately to apply the official patch addressing the inefficient parsing algorithm. 2. For environments where upgrading is not feasible, implement strict input validation and sanitization, specifically limiting the length of date strings accepted from user inputs to well below 10,000 characters. 3. Employ application-layer rate limiting and input throttling to reduce the risk of automated or bulk exploitation attempts. 4. Monitor application performance metrics and logs for unusual CPU spikes or slowdowns related to date parsing functions. 5. Conduct code audits and dependency reviews to identify and remediate any indirect usage of vulnerable moment.js versions in third-party libraries or microservices. 6. Consider adopting alternative date libraries with more efficient parsing algorithms if moment.js usage is extensive and cannot be fully controlled. 7. Integrate Web Application Firewalls (WAFs) with custom rules to detect and block excessively long or malformed date strings targeting the vulnerable parsing routines.