The vulnerability identified as CVE-2025-66031 affects the digitalbazaar forge library, commonly known as node-forge, which is a JavaScript implementation of Transport Layer Security (TLS) and cryptographic functions. The flaw is categorized under CWE-674 (Uncontrolled Recursion) and exists in versions 1.3.1 and earlier. The root cause is the lack of bounds checking on the recursion depth when parsing ASN.1 structures encoded in DER format. Attackers can craft malicious ASN.1 inputs with excessive nesting levels, causing the parser to recurse indefinitely until the call stack is exhausted. This results in a Denial-of-Service (DoS) condition by crashing or hanging the application that uses the vulnerable library. The vulnerability can be exploited remotely without any authentication or user interaction, simply by sending specially crafted DER data to the affected system. This makes it highly accessible to attackers. The issue was addressed in version 1.3.2 of node-forge by implementing recursion depth limits or other parsing safeguards to prevent stack exhaustion. No known exploits have been reported in the wild yet, but the high CVSS score of 8.7 indicates a serious risk. The vulnerability impacts any application or service that relies on node-forge for TLS or cryptographic operations, including web servers, client-side applications, and other JavaScript-based systems that parse ASN.1 data.

For European organizations, this vulnerability poses a significant risk of service disruption due to Denial-of-Service attacks. Since node-forge is widely used in JavaScript environments for TLS and cryptographic functions, affected applications could become unresponsive or crash when processing malicious ASN.1 inputs. This can lead to downtime, loss of availability, and potential cascading effects on dependent services. Industries relying heavily on secure communications, such as finance, healthcare, and government, may face operational interruptions. Additionally, the unauthenticated nature of the exploit means attackers can launch DoS attacks without prior access, increasing the threat surface. The impact is particularly critical for cloud services, web applications, and APIs that accept or process ASN.1 encoded data. Although no data confidentiality or integrity breach is indicated, the loss of availability alone can cause reputational damage and financial losses. Organizations using older versions of node-forge in their software stacks should prioritize remediation to avoid exploitation.

The primary mitigation is to upgrade all instances of the digitalbazaar forge (node-forge) library to version 1.3.2 or later, where the vulnerability has been patched. Organizations should audit their software dependencies to identify and update any affected versions. Additionally, implement input validation to restrict the maximum recursion depth or nesting level of ASN.1 structures before parsing. Employ runtime monitoring and anomaly detection to identify unusual parsing behavior or excessive resource consumption indicative of an attack. For web-facing services, consider deploying Web Application Firewalls (WAFs) with rules to detect and block malformed ASN.1 DER payloads. Developers should review and harden any custom ASN.1 parsing code to prevent similar recursion issues. Finally, maintain an incident response plan to quickly address potential DoS incidents and ensure system redundancy to minimize downtime.