Arch Linux Security Advisory ASA-202103-1 ========================================= Severity: Low Date : 2021-03-13 CVE-ID : CVE-2021-20231 CVE-2021-20232 Package : gnutls Type : arbitrary code execution Remote : Yes Link : https://security.archlinux.org/AVG-1674 Summary ======= The package gnutls before version 3.7.1-1 is vulnerable to arbitrary code execution. Resolution ========== Upgrade to 3.7.1-1. # pacman -Syu "gnutls>=3.7.1-1" The problems have been fixed upstream in version 3.7.1. Workaround ========== None. Description =========== - CVE-2021-20231 (arbitrary code execution) A security issue was found in GnuTLS before version 3.7.1. It was found that the client sending a "key_share" extension may result in dereferencing a pointer no longer valid after realloc(). This only happens in TLS 1.3 and only when the client sends a large Client Hello message, e.g., when HRR is sent in a resumed session previously negotiated large FFDHE parameters, because the initial allocation of the buffer is large enough without having to call realloc(). - CVE-2021-20232 (arbitrary code execution) A security issue was found in GnuTLS before version 3.7.1. It was found that the client sending a "pre_share_key" extension may result in dereferencing a pointer no longer valid after realloc(). This only happens in TLS 1.3 and only when the client sends a large Client Hello message, e.g., when HRR is sent in a resumed session previously negotiated large FFDHE parameters, because the initial allocation of the buffer is large enough without having to call realloc(). Impact ====== A remote attacker might be able to cause a denial of service or possibly execute arbitrary code when a TLS client is resuming a TLS 1.3 session. References ========== https://www.gnutls.org/security-new.html#GNUTLS-SA-2021-03-10 https://gitlab.com/gnutls/gnutls/-/issues/1151 https://gitlab.com/gnutls/gnutls/-/merge_requests/1399 https://gitlab.com/gnutls/gnutls/-/commit/15beb4b193b2714d88107e7dffca781798... https://gitlab.com/gnutls/gnutls/-/commit/75a937d97f4fefc6f9b08e3791f151445f... https://security.archlinux.org/CVE-2021-20231 https://security.archlinux.org/CVE-2021-20232