Red Hat Bugzilla – Bug 1301488
CVE-2015-7744 yaSSL, wolfSSL: insufficient hardening of RSA-CRT implementation (Oracle MySQL CPU Jan 2016)
Last modified: 2016-10-26 10:13:41 EDT
Vulnerability in the MySQL Server component of Oracle MySQL (subcomponent: Server: Security: Encryption). Supported versions that are affected are 5.5.45 and earlier and 5.6.26 and earlier. Very difficult to exploit vulnerability allows successful unauthenticated network attacks via multiple protocols. Successful attack of this vulnerability can result in unauthorized read access to a subset of MySQL Server accessible data. External References: http://www.oracle.com/technetwork/topics/security/cpujan2016verbose-2367956.html
Created mariadb tracking bugs for this issue: Affects: fedora-all [bug 1301518]
Created community-mysql tracking bugs for this issue: Affects: fedora-all [bug 1301517]
Created mariadb-galera tracking bugs for this issue: Affects: fedora-all [bug 1301519]
This actually is not a MySQL flaw, but a flaw in embedded yaSSL library. Mitre CVE description is: wolfSSL (formerly CyaSSL) before 3.6.8 does not properly handle faults associated with the Chinese Remainder Theorm (CRT) process when allowing ephemeral key exchange without low memory optimizations on a server, which makes it easier for remote attackers to obtain private RSA keys by capturing TLS handshakes, aka a Lenstra attack. References: https://wolfssl.com/wolfSSL/Blog/Entries/2015/9/17_Two_Vulnerabilities_Recently_Found%2C_An_Attack_on_RSA_using_CRT_and_DoS_Vulnerability_With_DTLS.html https://www.wolfssl.com/wolfSSL/Docs-yassl-changelog.html https://people.redhat.com/~fweimer/rsa-crt-leaks.pdf https://securityblog.redhat.com/2015/09/02/factoring-rsa-keys-with-tls-perfect-forward-secrecy/ Issue was fixed in MySQL by updating embedded yaSSL library to version 2.3.8: https://github.com/mysql/mysql-server/commit/b9768521bdeb1a8069c7b871f4536792b65fd79b MySQL and MariaDB packages as included in Red Hat products do not use embedded yaSSL library and rather use system OpenSSL. Therefore, they were not affected by this issue.