CWE-324 (使用已过期的密钥) — Vulnerability Class 19

CWE-324 represents a cryptographic weakness where software continues to utilize a key or password after its designated expiration date has passed. This oversight significantly diminishes security by expanding the temporal window available for attackers to perform brute-force or cryptanalytic attacks against the compromised credential. While expiration does not guarantee immediate compromise, prolonged usage increases the statistical probability of key exposure through accumulated data analysis or side-channel attacks. Developers can mitigate this risk by implementing robust key lifecycle management systems that automatically enforce rotation policies and revoke expired credentials. By integrating automated alerts and strict validation checks, organizations ensure that cryptographic materials are refreshed regularly, thereby minimizing the exposure window and maintaining the integrity of encrypted communications and stored sensitive data.