Security researchers at Codean Labs have discovered a severe vulnerability in the widely-used OpenPGP.js encryption library, potentially compromising the integrity of signed and encrypted communications. The flaw, assigned CVE-2025-47934 with a CVSS score of 8.7, affects versions 5 and 6 of the library, enabling attackers to forge seemingly legitimate signed messages.
Technical Analysis of the Vulnerability
The vulnerability exploits weaknesses in the signature verification process within OpenPGP.js’s core functions. Attackers can manipulate the openpgp.verify and openpgp.decrypt methods to bypass signature validation checks, allowing them to generate fraudulent messages that appear legitimately signed. This attack vector is particularly concerning as it affects both standalone signed messages and combined signed-encrypted communications.
Impact Assessment and Affected Systems
The security flaw impacts numerous popular applications and services that rely on OpenPGP.js, including FlowCrypt, Mymail-Crypt, UDC, Encrypt.to, PGP Anywhere, and Passbolt. Organizations using these applications for secure communications face potential risks of message forgery and unauthorized content manipulation. Version 4.x implementations remain unaffected by this vulnerability.
Mitigation Strategies and Security Updates
The OpenPGP.js development team has released security patches in versions 5.11.3 and 6.1.1 to address the vulnerability. Until systems can be updated, security experts recommend implementing a two-step verification process: first decrypting messages without verificationKeys, then separately validating signatures using openpgp.verify.
Best Practices for Affected Organizations
Security administrators should immediately implement the following measures:
– Update OpenPGP.js implementations to versions 5.11.3 or 6.1.1
– Conduct security audits of systems utilizing the affected library
– Review message verification procedures in existing applications
– Monitor for potential exploitation attempts in security logs
This incident highlights the critical importance of maintaining up-to-date cryptographic libraries and implementing robust signature verification mechanisms in secure communication systems. Organizations should establish regular security update protocols and conduct periodic assessments of their cryptographic implementations to prevent similar vulnerabilities from compromising their security infrastructure. The cybersecurity community continues to emphasize the significance of prompt patch management and comprehensive security testing in maintaining the integrity of encrypted communications.
