ssl/s3_clnt.c in OpenSSL 1.0.0 before 1.0.0t, 1.0.1 before 1.0.1p, and 1.0.2 before 1.0.2d, when used for a multi-threaded client, writes the PSK identity hint to an incorrect data structure, which allows remote servers to cause a denial of service (race condition and double free) via a crafted ServerKeyExchange message.

Affected: Ubuntu:14.04:LTS: openssl

Guy Leaver discovered that OpenSSL incorrectly handled a ServerKeyExchange for an anonymous DH ciphersuite with the value of p set to 0. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only applied to Ubuntu 15.10. (CVE-2015-1794)

Hanno Böck discovered that the OpenSSL Montgomery squaring procedure algorithm may produce incorrect results when being used on x86_64. A remote attacker could possibly use this issue to break encryption. This issue only applied to Ubuntu 15.10. (CVE-2015-3193)

Loïc Jonas Etienne discovered that OpenSSL incorrectly handled ASN.1 signatures with a missing PSS parameter. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2015-3194)

Adam Langley discovered that OpenSSL incorrectly handled malformed X509_ATTRIBUTE structures. A remote attacker could possibly use this issue to cause OpenSSL to consume resources, resulting in a denial of service. (CVE-2015-3195)

It was discovered that OpenSSL incorrectly handled PSK identity hints. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue only applied to Ubuntu 12.04 LTS, Ubuntu 14.04 LTS and Ubuntu 15.04. (CVE-2015-3196)