Incidents with OpenSSH and Security Compromises

There have been a few incidents in the past where security has been compromised with OpenSSH:

1. CVE-2008-0166 - Flaw in the implementation of the RSA/DSA signature verification process. This vulnerability could allow an attacker to execute arbitrary code on a targeted Debian system.




2. CVE-2015-4000 - Known as Logjam, a flaw in the Diffie-Hellman key exchange that allowed attackers to downgrade encryption strength, making it easier to decrypt HTTPS and SSH traffic. It was mitigated by increasing key sizes and disabling weak ciphers.




3. CVE-2016-5195 - Dirty COW was discovered in the Linux kernel, which is used by OpenSSH. This vulnerability allowed an attacker to gain root access to a targeted system.




4. CVE-2016-0777 - A vulnerability was discovered in the OpenSSH client that allowed an attacker to steal private keys from the memory of a compromised client system.




5. CVE-2023-48795 - Terrapin attack allows MitM adversaries to manipulate SSH sequence numbers, potentially downgrading security. It affects OpenSSH prior to version 9.6—update clients/servers and enforce modern security protocols to mitigate.