The ASN.1 implementation in OpenSSL before 1.0.1o and 1.0.2 before 1.0.2c allows remote attackers to execute arbitrary code or cause a denial of service (buffer underflow and memory corruption) via an ANY field in crafted serialized data, aka the "negative zero" issue.

Affected: Ubuntu:14.04:LTS: openssl, Ubuntu:16.04:LTS: openssl

Huzaifa Sidhpurwala, Hanno Böck, and David Benjamin discovered that OpenSSL incorrectly handled memory when decoding ASN.1 structures. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-2108)

Juraj Somorovsky discovered that OpenSSL incorrectly performed padding when the connection uses the AES CBC cipher and the server supports AES-NI. A remote attacker could possibly use this issue to perform a padding oracle attack and decrypt traffic. (CVE-2016-2107)

Guido Vranken discovered that OpenSSL incorrectly handled large amounts of input data to the EVP_EncodeUpdate() function. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-2105)

Guido Vranken discovered that OpenSSL incorrectly handled large amounts of input data to the EVP_EncryptUpdate() function. A remote attacker could use this issue to cause OpenSSL to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2016-2106)

Brian Carpenter discovered that OpenSSL incorrectly handled memory when ASN.1 data is read from a BIO. A remote attacker could possibly use this issue to cause memory consumption, resulting in a denial of service. (CVE-2016-2109)

As a security improvement, this update also modifies OpenSSL behaviour to reject DH key sizes below 1024 bits, preventing a possible downgrade attack.