7.8 - USN-3087-1

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

- Ubuntu 16.04 LTS - 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:

Shi Lei discovered that OpenSSL incorrectly handled the OCSP Status Request extension. A remote attacker could possibly use this issue to cause memory consumption, resulting in a denial of service. (CVE-2016-6304)

Guido Vranken discovered that OpenSSL used undefined behaviour when performing pointer arithmetic. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. This issue has only been addressed in Ubuntu 16.04 LTS in this update. (CVE-2016-2177)

César Pereida, Billy Brumley, and Yuval Yarom discovered that OpenSSL did not properly use constant-time operations when performing DSA signing. A remote attacker could possibly use this issue to perform a cache-timing attack and recover private DSA keys. (CVE-2016-2178)

Quan Luo discovered that OpenSSL did not properly restrict the lifetime of queue entries in the DTLS implementation. A remote attacker could possibly use this issue to consume memory, resulting in a denial of service. (CVE-2016-2179)

Shi Lei discovered that OpenSSL incorrectly handled memory in the TS_OBJ_print_bio() function. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-2180)

It was discovered that the OpenSSL incorrectly handled the DTLS anti-replay feature. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-2181)

Shi Lei discovered that OpenSSL incorrectly validated division results. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-2182)

Karthik Bhargavan and Gaetan Leurent discovered that the DES and Triple DES ciphers were vulnerable to birthday attacks. A remote attacker could possibly use this flaw to obtain clear text data from long encrypted sessions. This update moves DES from the HIGH cipher list to MEDIUM. (CVE-2016-2183)

Shi Lei discovered that OpenSSL incorrectly handled certain ticket lengths. A remote attacker could use this issue to cause a denial of service. (CVE-2016-6302)

Shi Lei discovered that OpenSSL incorrectly handled memory in the MDC2_Update() function. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-6303)

Shi Lei discovered that OpenSSL incorrectly performed certain message length checks. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2016-6306)

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-1ubuntu4.4

Ubuntu 14.04 LTS:
libssl1.0.0 1.0.1f-1ubuntu2.20

Ubuntu 12.04 LTS:
libssl1.0.0 1.0.1-4ubuntu5.37

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

References:
http://www.ubuntu.com/usn/usn-3087-1
CVE-2016-2177, CVE-2016-2178, CVE-2016-2179, CVE-2016-2180,
CVE-2016-2181, CVE-2016-2182, CVE-2016-2183, CVE-2016-6302,
CVE-2016-6303, CVE-2016-6304, CVE-2016-6306

Package Information:
https://launchpad.net/ubuntu/+source/openssl/1.0.2g-1ubuntu4.4
https://launchpad.net/ubuntu/+source/openssl/1.0.1f-1ubuntu2.20
https://launchpad.net/ubuntu/+source/openssl/1.0.1-4ubuntu5.37