Subject: [ASA-202009-5] gnupg: arbitrary code execution Arch Linux Security Advisory ASA-202009-5 ========================================= Severity: Critical Date : 2020-09-07 CVE-ID : CVE-2020-25125 Package : gnupg Type : arbitrary code execution Remote : Yes Link : https://security.archlinux.org/AVG-1218 Summary ======= The package gnupg before version 2.2.23-1 is vulnerable to arbitrary code execution. Resolution ========== Upgrade to 2.2.23-1. # pacman -Syu "gnupg>=2.2.23-1" The problem has been fixed upstream in version 2.2.23. Workaround ========== None. Description =========== Importing an OpenPGP key having a preference list for AEAD algorithms will lead to an array overflow and thus often to a crash or other undefined behaviour. Importing an arbitrary key can often easily be triggered by an attacker and thus triggering this bug. Exploiting the bug aside from crashes is not trivial but likely possible for a dedicated attacker. The major hurdle for an attacker is that only every second byte is under their control with every first byte having a fixed value of 0x04. Software distribution verification should not be affected by this bug because such a system uses a curated list of keys. Impact ====== A remote attacker might be able to execute arbitrary code by tricking a legitimate user into importing a crafted OpenPGP key. References ========== https://lists.gnupg.org/pipermail/gnupg-announce/2020q3/000448.html https://dev.gnupg.org/T5050 https://security.archlinux.org/CVE-2020-25125