In jenkins/ssh-agent Docker images 6.11.1 and earlier, SSH host keys are generated on image creation for images based on Debian, causing all containers based on images of the same version use the same SSH host keys, allowing attackers able to insert themselves into the network path between the SSH client (typically the Jenkins controller) and SSH build agent to impersonate the latter.
The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG’s algorithm is not cryptographically strong.
When a non-cryptographic PRNG is used in a cryptographic context, it can expose the cryptography to certain types of attacks. Often a pseudo-random number generator (PRNG) is not designed for cryptography. Sometimes a mediocre source of randomness is sufficient or preferable for algorithms that use random numbers. Weak generators generally take less processing power and/or do not use the precious, finite, entropy sources on a system. While such PRNGs might have very useful features, these same features could be used to break the cryptography.