Arch Linux Security Advisory ASA-202004-18 ========================================== Severity: High Date : 2020-04-21 CVE-ID : CVE-2020-1967 Package : openssl Type : denial of service Remote : Yes Link : https://security.archlinux.org/AVG-1139 Summary ======= The package openssl before version 1.1.1.g-1 is vulnerable to denial of service. Resolution ========== Upgrade to 1.1.1.g-1. # pacman -Syu "openssl>=1.1.1.g-1" The problem has been fixed upstream in version 1.1.1.g. Workaround ========== None. Description =========== A NULL pointer dereference has been found in OpenSSL versions 1.1.1d, 1.1.1e and 1.1.1f. Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake may crash due to a NULL pointer dereference as a result of incorrect handling of the "signature_algorithms_cert" TLS extension. The crash occurs if an invalid or unrecognised signature algorithm is received from the peer. This could be exploited by a malicious peer in a Denial of Service attack. Impact ====== A malicious server or client may crash an openssl/libssl process by providing a maliciously-crafted SSL handshake References ========== https://www.openssl.org/news/secadv/20200421.txt https://github.com/openssl/openssl/commit/eb563247aef3e83dda7679c43f96492704... https://security.archlinux.org/CVE-2020-1967