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Ubuntu Security Notice USN-6640-1
February 15, 2024

shadow vulnerability

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

• Ubuntu 23.10
• Ubuntu 22.04 LTS
• Ubuntu 20.04 LTS
• Ubuntu 18.04 LTS (Available with Ubuntu Pro)
• Ubuntu 16.04 LTS (Available with Ubuntu Pro)
• Ubuntu 14.04 LTS (Available with Ubuntu Pro)

Summary:

shadow could be made to expose sensitive information.

Software Description:

• shadow: system login tools

Details:

It was discovered that shadow was not properly sanitizing memory when
running the password utility. An attacker could possibly use this issue
to retrieve a password from memory, exposing sensitive information.

Update instructions:

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

Ubuntu 23.10:
libsubid-dev 1:4.13+dfsg1-1ubuntu1.1
libsubid4 1:4.13+dfsg1-1ubuntu1.1
login 1:4.13+dfsg1-1ubuntu1.1
passwd 1:4.13+dfsg1-1ubuntu1.1
uidmap 1:4.13+dfsg1-1ubuntu1.1

Ubuntu 22.04 LTS:
login 1:4.8.1-2ubuntu2.2
passwd 1:4.8.1-2ubuntu2.2
uidmap 1:4.8.1-2ubuntu2.2

Ubuntu 20.04 LTS:
login 1:4.8.1-1ubuntu5.20.04.5
passwd 1:4.8.1-1ubuntu5.20.04.5
uidmap 1:4.8.1-1ubuntu5.20.04.5

Ubuntu 18.04 LTS (Available with Ubuntu Pro):
login 1:4.5-1ubuntu2.5+esm1
passwd 1:4.5-1ubuntu2.5+esm1
uidmap 1:4.5-1ubuntu2.5+esm1

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
login 1:4.2-3.1ubuntu5.5+esm4
passwd 1:4.2-3.1ubuntu5.5+esm4
uidmap 1:4.2-3.1ubuntu5.5+esm4

Ubuntu 14.04 LTS (Available with Ubuntu Pro):
login 1:4.1.5.1-1ubuntu9.5+esm4
passwd 1:4.1.5.1-1ubuntu9.5+esm4
uidmap 1:4.1.5.1-1ubuntu9.5+esm4

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

References:
https://ubuntu.com/security/notices/USN-6640-1
CVE-2023-4641

Package Information:
https://launchpad.net/ubuntu/+source/shadow/1:4.13+dfsg1-1ubuntu1.1
https://launchpad.net/ubuntu/+source/shadow/1:4.8.1-2ubuntu2.2
https://launchpad.net/ubuntu/+source/shadow/1:4.8.1-1ubuntu5.20.04.5