1. Ubuntu Security Notices
  2. USN-5168-4

USN-5168-4: NSS regression

Publication date

7 December 2021

Overview

USN-5168-3 introduced a regression in NSS.

Releases

Packages

  • nss - Network Security Service library

Details

USN-5168-3 fixed a vulnerability in NSS. Unfortunately that update introduced
a regression that could break SSL connections. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Tavis Ormandy discovered that NSS incorrectly handled verifying DSA/RSA-PSS
signatures. A remote attacker could use this issue to cause NSS to crash,
resulting in a denial of service, or possibly execute arbitrary code.

USN-5168-3 fixed a vulnerability in NSS. Unfortunately that update introduced
a regression that could break SSL connections. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

Tavis Ormandy discovered that NSS incorrectly handled verifying DSA/RSA-PSS
signatures. A remote attacker could use this issue to cause NSS to crash,
resulting in a denial of service, or possibly execute arbitrary code.

Update instructions

After a standard system update you need to restart any applications that use NSS, such as Evolution, to 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
16.04 xenial libnss3 –  2:3.28.4-0ubuntu0.16.04.14+esm2  
14.04 trusty libnss3 –  2:3.28.4-0ubuntu0.14.04.5+esm10  

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References

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