SSL/TLS certificates with weak cryptographic keys or signature algorithms pose significant security risks, leaving systems vulnerable to cryptographic attacks.

Key points about weak cryptographic keys and signature algorithms:

1. Weak Cryptographic Keys:
- RSA Keys: RSA keys shorter than 2048 bits are considered weak. The current recommendation is to use at least 2048 bits, with 3072 bits or higher for long-term security.
- DSA Keys: Similar to RSA, DSA keys shorter than 2048 bits are considered weak and should be avoided.
- Computational Advances: As computational power increases, shorter key lengths become increasingly vulnerable to attacks.
- Industry Standards: Many industry standards and compliance requirements mandate minimum key lengths for SSL/TLS certificates.

2. Weak Signature Algorithms:
- Obsolete Algorithms: MD5 and SHA1 are considered cryptographically broken and should not be used.
- Collision Attacks: Weak algorithms are vulnerable to collision attacks, where an attacker can create a fraudulent certificate with the same signature as a legitimate one.
- Industry Standards: Many industry standards and compliance requirements prohibit the use of weak signature algorithms.
- Backwards Compatibility: Some systems may still use weak algorithms for backwards compatibility, but this practice is strongly discouraged.

**Real-World Implications:**
A website using a certificate with a 1024-bit RSA key or signed with SHA1 could be targeted by attackers with significant computational resources. They could decrypt intercepted traffic or create forged certificates, enabling man-in-the-middle attacks and compromising the security of communications. As such, adherence to industry standards requiring strong keys and algorithms is essential to maintaining SSL/TLS security.