USN-2959-1: OpenSSL vulnerabilities

Ubuntu Security Notice USN-2959-1

3rd May, 2016

openssl vulnerabilities

A security issue affects these releases of Ubuntu and its
derivatives:

Ubuntu 16.04 LTS
Ubuntu 15.10
Ubuntu 14.04 LTS
Ubuntu 12.04 LTS

Summary

Several security issues were fixed in OpenSSL.

Software description

openssl
– Secure Socket Layer (SSL) cryptographic library and tools

Details

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.