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Ubuntu Security Notice USN-3181-1
January 31, 2017

openssl vulnerabilities
===========================================================================

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 =C5=9Awi=C4=99cki 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