CVE-2022-25898: 
JavaScript vulnerability analysis and mitigation

The vulnerability CVE-2022-25898 affects the jsrsasign package versions before 10.5.25. This security flaw was discovered in June 2022 and involves improper verification of cryptographic signatures in JSON Web Signatures (JWS) and JSON Web Tokens (JWT). The vulnerability allows non-Base64URL encoding special characters or number escaped characters to be incorrectly validated as valid signatures (NVD, Snyk).

The vulnerability stems from improper validation of JWS and JWT signatures, where the verification methods JWS.verify() and JWS.verifyJWT() may incorrectly accept signatures containing special characters or escaped numeric characters that don't conform to Base64URL encoding standards. The issue has been assigned a CVSS v3.1 base score of 9.8 (CRITICAL) by NVD and 7.7 (HIGH) by Snyk, indicating its severe impact on system security (NVD, Snyk).

The vulnerability could allow attackers to bypass signature verification mechanisms, potentially leading to unauthorized access or manipulation of protected resources. This could compromise the integrity and authenticity of JWT-based authentication systems, affecting applications that rely on jsrsasign for cryptographic operations (Snyk).

The primary mitigation is to upgrade jsrsasign to version 10.5.25 or higher, which includes the security fix. As a workaround, developers should validate that JWS or JWT signatures contain only Base64URL and dot-safe strings before executing JWS.verify() or JWS.verifyJWT() methods (GitHub Release, GitHub Commit).