10 - USN-2959-1

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.

Update instructions:

The problem can be corrected by updating your system to the following package versions:

Ubuntu 16.04 LTS:
libssl1.0.0 1.0.2g-1ubuntu4.1

Ubuntu 15.10:
libssl1.0.0 1.0.2d-0ubuntu1.5

Ubuntu 14.04 LTS:
libssl1.0.0 1.0.1f-1ubuntu2.19

Ubuntu 12.04 LTS:
libssl1.0.0 1.0.1-4ubuntu5.36

After a standard system update you need to reboot your computer to make all the necessary changes.

References:
http://www.ubuntu.com/usn/usn-2959-1
CVE-2016-2105, CVE-2016-2106, CVE-2016-2107, CVE-2016-2108,
CVE-2016-2109

Package Information:
https://launchpad.net/ubuntu/+source/openssl/1.0.2g-1ubuntu4.1
https://launchpad.net/ubuntu/+source/openssl/1.0.2d-0ubuntu1.5
https://launchpad.net/ubuntu/+source/openssl/1.0.1f-1ubuntu2.19
https://launchpad.net/ubuntu/+source/openssl/1.0.1-4ubuntu5.36