CVE-2017-18205
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (2.04%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.0
- 8.1 HIGHCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.04% probability · 81th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-476
- Affected
- zsh project/zsh
- Source
- cve@mitre.org
EPSS 2.0% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://access.redhat.com/errata/RHSA-2018:3073
- https://security.gentoo.org/glsa/201805-10
- https://sourceforge.net/p/zsh/code/ci/eb783754bdb74377f3cea4ceca9c23a02ea1bf58Patch, Third Party Advisory
- https://usn.ubuntu.com/3593-1/
- https://access.redhat.com/errata/RHSA-2018:3073
- https://security.gentoo.org/glsa/201805-10
- https://sourceforge.net/p/zsh/code/ci/eb783754bdb74377f3cea4ceca9c23a02ea1bf58Patch, Third Party Advisory
- https://usn.ubuntu.com/3593-1/
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.