CWE-298 (证书过期验证不恰当) — Vulnerability Class 4

CWE-298 represents a critical cryptographic weakness where software fails to properly validate the expiration date of digital certificates. This flaw typically allows attackers to exploit trust relationships by presenting expired or revoked certificates, effectively bypassing authentication mechanisms and enabling man-in-the-middle attacks. By ignoring expiration checks, developers inadvertently permit malicious actors to impersonate legitimate services or intercept sensitive data without detection. To mitigate this risk, developers must implement robust validation logic that strictly verifies certificate validity periods against current system time during every connection establishment. Utilizing established cryptographic libraries that automatically handle expiration checks, rather than relying on custom implementations, ensures consistent enforcement. Additionally, integrating Certificate Revocation List (CRL) or Online Certificate Status Protocol (OCSP) checks provides an extra layer of security, ensuring that even validly dated certificates are not compromised due to prior revocation.