7.5 - USN-3181-1

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

- Ubuntu 16.10 - 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:

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 only applied to Ubuntu 12.04 LTS and Ubuntu 14.04 LTS as other releases were fixed in a previous security update. (CVE-2016-2177)

It was discovered that OpenSSL did not properly handle Montgomery multiplication, resulting in incorrect results leading to transient failures. This issue only applied to Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2016-7055)

It was discovered that OpenSSL did not properly use constant-time operations when performing ECDSA P-256 signing. A remote attacker could possibly use this issue to perform a timing attack and recover private ECDSA keys. This issue only applied to Ubuntu 12.04 LTS and Ubuntu 14.04 LTS. (CVE-2016-7056)

Shi Lei discovered that OpenSSL incorrectly handled certain warning alerts. A remote attacker could possibly use this issue to cause OpenSSL to stop responding, resulting in a denial of service. (CVE-2016-8610)

Robert Święcki discovered that OpenSSL incorrectly handled certain truncated packets. A remote attacker could possibly use this issue to cause OpenSSL to crash, resulting in a denial of service. (CVE-2017-3731)

It was discovered that OpenSSL incorrectly performed the x86_64 Montgomery squaring procedure. While unlikely, a remote attacker could possibly use this issue to recover private keys. This issue only applied to Ubuntu 16.04 LTS, and Ubuntu 16.10. (CVE-2017-3732)

Update instructions:

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

Ubuntu 16.10:
libssl1.0.0 1.0.2g-1ubuntu9.1

Ubuntu 16.04 LTS:
libssl1.0.0 1.0.2g-1ubuntu4.6

Ubuntu 14.04 LTS:
libssl1.0.0 1.0.1f-1ubuntu2.22

Ubuntu 12.04 LTS:
libssl1.0.0 1.0.1-4ubuntu5.39

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

References:
http://www.ubuntu.com/usn/usn-3181-1
CVE-2016-2177, CVE-2016-7055, CVE-2016-7056, CVE-2016-8610,
CVE-2017-3731, CVE-2017-3732

Package Information:
https://launchpad.net/ubuntu/+source/openssl/1.0.2g-1ubuntu9.1
https://launchpad.net/ubuntu/+source/openssl/1.0.2g-1ubuntu4.6
https://launchpad.net/ubuntu/+source/openssl/1.0.1f-1ubuntu2.22
https://launchpad.net/ubuntu/+source/openssl/1.0.1-4ubuntu5.39