1. Ubuntu Security Notices
  2. USN-3339-1

USN-3339-1: OpenVPN vulnerabilities

Publication date

22 June 2017

Overview

Several security issues were fixed in OpenVPN.

Releases

Packages

  • openvpn - virtual private network software

Details

Karthikeyan Bhargavan and Gaëtan Leurent discovered that 64-bit block
ciphers are vulnerable to a birthday attack. A remote attacker could
possibly use this issue to recover cleartext data. Fixing this issue
requires a configuration change to switch to a different cipher. This
update adds a warning to the log file when a 64-bit block cipher is in use.
This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and
Ubuntu 16.10. (CVE-2016-6329)

It was discovered that OpenVPN incorrectly handled rollover of packet ids.
An authenticated remote attacker could use this issue to cause OpenVPN to
crash, resulting in a denial of service. This issue only affected Ubuntu
14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2017-7479)

Guido Vranken discovered that OpenVPN incorrectly handled certain malformed
IPv6 packets. A remote attacker could use this issue to...

Karthikeyan Bhargavan and Gaëtan Leurent discovered that 64-bit block
ciphers are vulnerable to a birthday attack. A remote attacker could
possibly use this issue to recover cleartext data. Fixing this issue
requires a configuration change to switch to a different cipher. This
update adds a warning to the log file when a 64-bit block cipher is in use.
This issue only affected Ubuntu 14.04 LTS, Ubuntu 16.04 LTS and
Ubuntu 16.10. (CVE-2016-6329)

It was discovered that OpenVPN incorrectly handled rollover of packet ids.
An authenticated remote attacker could use this issue to cause OpenVPN to
crash, resulting in a denial of service. This issue only affected Ubuntu
14.04 LTS, Ubuntu 16.04 LTS and Ubuntu 16.10. (CVE-2017-7479)

Guido Vranken discovered that OpenVPN incorrectly handled certain malformed
IPv6 packets. A remote attacker could use this issue to cause OpenVPN to
crash, resulting in a denial of service. (CVE-2017-7508)

Guido Vranken discovered that OpenVPN incorrectly handled an HTTP proxy
with NTLM authentication. A remote attacker could use this issue to cause
OpenVPN clients to crash, resulting in a denial of service, or possibly
expose sensitive memory contents. (CVE-2017-7520)

Guido Vranken discovered that OpenVPN incorrectly handled certain x509
extensions. A remote attacker could use this issue to cause OpenVPN to
crash, resulting in a denial of service. (CVE-2017-7521)

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
17.04 zesty openvpn –  2.4.0-4ubuntu1.3
16.10 yakkety openvpn –  2.3.11-1ubuntu2.1
16.04 xenial openvpn –  2.3.10-1ubuntu2.1
14.04 trusty openvpn –  2.3.2-7ubuntu3.2

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References

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