[USN-6728-2] Squid regression

USN-6728-1 fixed vulnerabilities in Squid. The fix for CVE-2023-5824 caused
Squid to crash in certain environments on Ubuntu 20.04 LTS. The problematic
fix has been reverted pending further investigation.

We apologize for the inconvenience.

Original advisory details:

Joshua Rogers discovered that Squid incorrectly handled collapsed
forwarding. A remote attacker could possibly use this issue to cause Squid
to crash, resulting in a denial of service. This issue only affected Ubuntu
20.04 LTS and Ubuntu 22.04 LTS. (CVE-2023-49288)

Joshua Rogers discovered that Squid incorrectly handled certain structural
elements. A remote attacker could possibly use this issue to cause Squid to
crash, resulting in a denial of service. (CVE-2023-5824)

Joshua Rogers discovered that Squid incorrectly handled Cache Manager error
responses. A remote trusted client can possibly use this issue to cause
Squid to crash, resulting in a denial of service. (CVE-2024-23638)

Joshua Rogers discovered that Squid incorrectly handled the HTTP Chunked
decoder. A remote attacker could possibly use this issue to cause Squid to
stop responding, resulting in a denial of service. (CVE-2024-25111)

Joshua Rogers discovered that Squid incorrectly handled HTTP header
parsing. A remote trusted client can possibly use this issue to cause
Squid to crash, resulting in a denial of service. (CVE-2024-25617)