Overview
CVE-2025-66031 describes a critical vulnerability affecting versions 1.3.1 and below of Forge (also known as node-forge), a native JavaScript implementation of Transport Layer Security (TLS). This vulnerability, an uncontrolled recursion issue in ASN.1 parsing, allows unauthenticated, remote attackers to trigger a Denial-of-Service (DoS) attack by crafting deeply nested ASN.1 structures. When node-forge attempts to parse these malicious structures, it leads to unbounded recursive parsing, resulting in stack exhaustion and ultimately a DoS.
Technical Details
The vulnerability resides in how node-forge handles ASN.1 (Abstract Syntax Notation One) structures, a standard for data serialization. Specifically, when parsing DER (Distinguished Encoding Rules) encoded data, the library fails to properly limit the depth of nested structures. An attacker can exploit this by creating a malicious DER input containing excessively nested ASN.1 objects. When node-forge attempts to decode this input, the parsing process enters an uncontrolled recursive loop. Each recursive call consumes stack memory. The excessively deep recursion quickly exhausts the available stack space, causing the process to crash and resulting in a Denial-of-Service.
CVSS Analysis
Due to the timing of disclosure, a CVSS score has not yet been assigned for CVE-2025-66031. However, given the potential for remote, unauthenticated DoS, it is likely to receive a high to critical CVSS score. This is because the attack does not require any prior authentication or user interaction and can severely impact the availability of services relying on vulnerable node-forge versions.
Possible Impact
The primary impact of CVE-2025-66031 is a Denial-of-Service. Successful exploitation can lead to:
- Application crashes
- Service unavailability
- Disruption of critical business processes
Applications that use node-forge for processing untrusted data (e.g., X.509 certificates, cryptographic keys) received from external sources are particularly vulnerable. This includes web servers, API endpoints, and other network services.
Mitigation or Patch Steps
The vulnerability has been patched in node-forge version 1.3.2. The primary mitigation is to upgrade to version 1.3.2 or later as soon as possible. Steps to mitigate this vulnerability include:
- Upgrade
node-forge: Update your project’s dependency onnode-forgeto version 1.3.2 or later. Use your project’s package manager (e.g., npm, yarn) to perform the upgrade. For example, using npm:npm install node-forge@latest - Verify the Upgrade: After upgrading, verify that the correct version of
node-forgeis being used by your application. - Code Review (Recommended): Review your code to identify areas where
node-forgeis used to parse potentially untrusted ASN.1 or DER data.
