NULL Pointer Dereference Affecting zsh package, versions <5.4.1-1
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.
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Test your applications- Snyk IDSNYK-DEBIAN14-ZSH-11775231
- published10 Aug 2025
- disclosed27 Feb 2018
Introduced: 27 Feb 2018
CVE-2017-18205 (opens in a new tab)How to fix?
Upgrade Debian:14 zsh to version 5.4.1-1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream zsh package and not the zsh package as distributed by Debian.
See How to fix? for Debian:14 relevant fixed versions and status.
In builtin.c in zsh before 5.4, when sh compatibility mode is used, there is a NULL pointer dereference during processing of the cd command with no argument if HOME is not set.
References
- https://security-tracker.debian.org/tracker/CVE-2017-18205
- https://security.gentoo.org/glsa/201805-10
- https://sourceforge.net/p/zsh/code/ci/eb783754bdb74377f3cea4ceca9c23a02ea1bf58
- https://access.redhat.com/errata/RHSA-2018:3073
- http://people.ubuntu.com/~ubuntu-security/cve/CVE-2017-18205
- https://usn.ubuntu.com/3593-1/