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Ubuntu Security Notice USN-6409-1
October 03, 2023
glibc vulnerabilities
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 23.04
- Ubuntu 22.04 LTS
Summary:
Several security issues were fixed in GNU C Library.
Software Description:
- glibc: GNU C Library
Details:
It was discovered that the GNU C Library incorrectly handled the
GLIBC_TUNABLES environment variable. An attacker could possibly use this
issue to perform a privilege escalation attack. (CVE-2023-4911)
It was discovered that the GNU C Library incorrectly handled certain DNS
responses when the system was configured in no-aaaa mode. A remote attacker
could possibly use this issue to cause the GNU C Library to crash,
resulting in a denial of service. This issue only affected Ubuntu 23.04.
(CVE-2023-4527)
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 23.04:
   libc6                           2.37-0ubuntu2.1
Ubuntu 22.04 LTS:
   libc6                           2.35-0ubuntu3.4
After a standard system update you need to reboot your computer to make all
the necessary changes.
References:
   https://ubuntu.com/security/notices/USN-6409-1
   CVE-2023-4527, CVE-2023-4911
Package Information:
   https://launchpad.net/ubuntu/+source/glibc/2.37-0ubuntu2.1
   https://launchpad.net/ubuntu/+source/glibc/2.35-0ubuntu3.4