Exploit/Advisories

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Ubuntu Security Notice USN-6727-2
April 11, 2024

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

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS

Summary:

USN-6727-1 introduced a regression in NSS.

Software Description:
- nss: Network Security Service library

Details:

USN-6727-1 fixed vulnerabilities in NSS. The update introduced a regression
when trying to load security modules on Ubuntu 20.04 LTS and Ubuntu 22.04
LTS. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that NSS incorrectly handled padding when checking PKCS#1
certificates. A remote attacker could possibly use this issue to perform
Bleichenbacher-like attacks and recover private data. This issue only
affected Ubuntu 20.04 LTS. (CVE-2023-4421)
It was discovered that NSS had a timing side-channel when performing RSA
decryption. A remote attacker could possibly use this issue to recover
private data. (CVE-2023-5388)
It was discovered that NSS had a timing side-channel when using certain
NIST curves. A remote attacker could possibly use this issue to recover
private data. (CVE-2023-6135)
The NSS package contained outdated CA certificates. This update refreshes
the NSS package to version 3.98 which includes the latest CA certificate
bundle and other security improvements.

Update instructions:

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

Ubuntu 22.04 LTS:
libnss3 2:3.98-0ubuntu0.22.04.2

Ubuntu 20.04 LTS:
libnss3 2:3.98-0ubuntu0.20.04.2

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

References:
https://ubuntu.com/security/notices/USN-6727-2
https://ubuntu.com/security/notices/USN-6727-1
https://launchpad.net/bugs/2060906

Package Information:
https://launchpad.net/ubuntu/+source/nss/2:3.98-0ubuntu0.22.04.2
https://launchpad.net/ubuntu/+source/nss/2:3.98-0ubuntu0.20.04.2