What’s Vulnerable › Vulnerabilities

CVE-2018-0502

• Severity: critical (CVSS 9.8 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-09-05 · updated 2026-06-17
• Weakness: CWE-20

Description

An issue was discovered in zsh before 5.6. The beginning of a #! script file was mishandled, potentially leading to an execve call to a program named on the second line.

Affected products

• Canonical Ubuntu Linux: 14.04, 16.04, 18.04
• zsh: before 5.6 — fixed in 5.6

How to fix

Upgrade to a fixed version: zsh 5.6. Check the vendor advisory for mitigations.

References

• https://bugs.debian.org/908000
• https://lists.debian.org/debian-lts-announce/2020/12/msg00000.html
• https://security.gentoo.org/glsa/201903-02
• https://sourceforge.net/p/zsh/code/ci/1c4c7b6a4d17294df028322b70c53803a402233d
• https://usn.ubuntu.com/3764-1/
• https://www.zsh.org/mla/zsh-announce/136
• https://bugs.debian.org/908000
• https://lists.debian.org/debian-lts-announce/2020/12/msg00000.html
• https://security.gentoo.org/glsa/201903-02
• https://sourceforge.net/p/zsh/code/ci/1c4c7b6a4d17294df028322b70c53803a402233d
• https://usn.ubuntu.com/3764-1/
• https://www.zsh.org/mla/zsh-announce/136

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