Arch Linux Security Advisory ASA-201507-8 ========================================= Severity: High Date : 2015-07-09 CVE-ID : CVE-2015-1793 Package : openssl Type : man-in-the-middle Remote : Yes Link : https://wiki.archlinux.org/index.php/CVE Summary ======= The package openssl before version 1.0.2.d-1 is vulnerable to man-in-the-middle. Resolution ========== Upgrade to 1.0.2.d-1. # pacman -Syu "openssl>=1.0.2.d-1" The problem has been fixed upstream in version 1.0.2.d. Workaround ========== None. Description =========== During certificate verification, OpenSSL will attempt to find an alternative certificate chain if the first attempt to build such a chain fails. An error in the implementation of this logic can mean that an attacker could cause certain checks on untrusted certificates to be bypassed, such as the CA flag, enabling them to use a valid leaf certificate to act as a CA and "issue" an invalid certificate. This issue will impact any application that verifies certificates including SSL/TLS/DTLS clients and SSL/TLS/DTLS servers using client authentication. Impact ====== A remote attacker is able to use a valid leaf certificate to act as a CA and "issue" an invalid certificate that behaves valid to possibly perform a man-in-the-middle attack. References ========== https://openssl.org/news/secadv_20150709.txt https://access.redhat.com/security/cve/CVE-2015-1793