Arch Linux Security Advisory ASA-201804-5 ========================================= Severity: High Date : 2018-04-11 CVE-ID : CVE-2018-1100 Package : zsh Type : arbitrary code execution Remote : No Link : https://security.archlinux.org/AVG-669 Summary ======= The package zsh before version 5.5-1 is vulnerable to arbitrary code execution. Resolution ========== Upgrade to 5.5-1. # pacman -Syu "zsh>=5.5-1" The problem has been fixed upstream in version 5.5. Workaround ========== None. Description =========== A stack-based buffer overflow has been found in zsh <= 5.4.2, in the checkmailpath() function, where unchecked strings from the MAILCHECK variable are copied to a buffer. A local, unprivileged user can create a specially crafted message file, which, if used to set a custom "you have new mail" message, leads to code execution in the context of the user who receives the message. If the user affected is privileged, this leads to privilege escalation. Impact ====== A local attacker might be able to execute arbitrary code in the context of another user. References ========== https://www.zsh.org/mla/workers/2018/msg00411.html https://sourceforge.net/p/zsh/code/ci/31f72205630687c1cef89347863aab355296a2... https://security.archlinux.org/CVE-2018-1100