Adam Langley

A double free vulnerability in the dsa priv decode function in crypto/dsa/dsa ameth.c in OpenSSL allows remote attackers to cause a denial of service (memory corruption) or possibly have unspecified other impact via a malformed DSA private key. Additionally, a side-channel attack was found which makes use of cache-bank conflicts on the Intel Sandy-Bridge microarchitecture which could lead to the recovery of RSA keys. A vulnerability in the MySQL Server component of Oracle MySQL allows high privileged attackers with network access via multiple protocols to compromise MySQL Server, resulting in unauthorized ability to cause a hang or frequently repeatable crash of MySQL Server.

The issue is related to the implementation of ASN1 TFLG COMBINE in the OpenSSL library, specifically in the crypto/asn1/tasn dec.c file. It is associated with a lack of protection for service data. Exploitation of this issue may allow a remote attacker to obtain sensitive information from the process memory. This can occur by triggering a decoding failure in a PKCS#7 or CMS application using malformed X509 ATTRIBUTE data.

The issue is related to the processing of X.509 Basic Constraints cA values during the identification of alternative certificate chains, which can allow remote attackers to spoof a Certification Authority role and trigger unintended certificate verifications via a valid leaf certificate. This can enable an attacker to forge "trusted" certificates that could be used to conduct man-in-the-middle attacks. The vulnerability affects applications that verify certificates, including SSL/Transport Layer Security (TLS)/Datagram Transport Layer Security (DTLS) clients and SSL/TLS/DTLS servers using client authentication.

The issue concerns the TLS protocol 1.1 and 1.2 and the DTLS protocol 1.0 and 1.2, which do not properly consider timing side-channel attacks on a MAC check requirement during the processing of malformed CBC padding. This allows remote attackers to conduct distinguishing attacks and plaintext-recovery attacks via statistical analysis of timing data for crafted packets, also known as the "Lucky Thirteen" issue.