OpenSSH 9.5 through 9.7 before 9.8 sometimes allows timing attacks against echo-off password entry (e.g., for su and Sudo) because of an ObscureKeystrokeTiming logic error. Similarly, other timing attacks against keystroke entry could occur.

References

• https://nvd.nist.gov/vuln/detail/CVE-2024-39894
• https://lists.mindrot.org/pipermail/openssh-unix-announce/2024-July/000158.html
• https://www.openssh.com/txt/release-9.8
• https://www.openwall.com/lists/oss-security/2024/07/02/1
• http://www.openwall.com/lists/oss-security/2024/07/03/6
• https://security.netapp.com/advisory/ntap-20240712-0004
• http://www.openwall.com/lists/oss-security/2024/07/23/4
• http://www.openwall.com/lists/oss-security/2024/07/23/6
• http://www.openwall.com/lists/oss-security/2024/07/28/3
• https://crzphil.github.io/posts/ssh-obfuscation-bypass
• https://news.ycombinator.com/item?id=41508530