Observable Timing Discrepancy Affecting openssh-portable package, versions [9.5,9.8p1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-UNMANAGED-OPENSSHPORTABLE-7420337
- published4 Jul 2024
- disclosed2 Jul 2024
- creditPhilippos Giavridis, Jacky Wei En Kung, Daniel Hugenroth, Alastair Beresford
Introduced: 2 Jul 2024
CVE-2024-39894 (opens in a new tab)How to fix?
Upgrade openssh-portable to version 9.8p1 or higher.
Overview
Affected versions of this package are vulnerable to Observable Timing Discrepancy due to a logic error in the ObscureKeystrokeTiming feature. An attacker can detect which packets contain real keystrokes even when this feature is enabled.
Additionally, the same logic error undermined the mitigation against information leakage when using echo-off mode in a TTY (e.g. for su or sudo).
Workaround
This vulnerability can be avoided by setting ObscureKeystrokeTiming=no, and does not apply to non-TTY sessions.