Recursive PROMPT_SUBST Expansion Vulnerability in zsh (CVE-2021-21409)

CVE-2021-45444 · HIGH Severity

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

In zsh before 5.8.1, an attacker can achieve code execution if they control a command output inside the prompt, as demonstrated by a %F argument. This occurs because of recursive PROMPT_SUBST expansion.

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