What’s Vulnerable › Vulnerabilities

CVE-2017-18206

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 3.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-02-27 · updated 2026-06-17
• Weakness: CWE-119

Description

In utils.c in zsh before 5.4, symlink expansion had a buffer overflow.

Affected products

• Canonical Ubuntu Linux: 14.04, 16.04, 17.10
• zsh: before 5.4 — fixed in 5.4

How to fix

Upgrade to a fixed version: zsh 5.4. Check the vendor advisory for mitigations.

References

• https://access.redhat.com/errata/RHSA-2018:1932
• https://access.redhat.com/errata/RHSA-2018:3073
• https://lists.debian.org/debian-lts-announce/2020/12/msg00000.html
• https://security.gentoo.org/glsa/201805-10
• https://sourceforge.net/p/zsh/code/ci/c7a9cf465dd620ef48d586026944d9bd7a0d5d6d
• https://usn.ubuntu.com/3593-1/
• https://access.redhat.com/errata/RHSA-2018:1932
• https://access.redhat.com/errata/RHSA-2018:3073
• https://lists.debian.org/debian-lts-announce/2020/12/msg00000.html
• https://security.gentoo.org/glsa/201805-10
• https://sourceforge.net/p/zsh/code/ci/c7a9cf465dd620ef48d586026944d9bd7a0d5d6d
• https://usn.ubuntu.com/3593-1/

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