USN-4981-1: Squid vulnerabilities

03 June 2021

Several security issues were fixed in Squid.

Releases

Packages

  • squid - Web proxy cache server
  • squid3 - Web proxy cache server

Details

Joshua Rogers discovered that Squid incorrectly handled requests with the
urn: scheme. A remote attacker could possibly use this issue to cause
Squid to consume resources, leading to a denial of service.
(CVE-2021-28651)

Joshua Rogers discovered that Squid incorrectly handled requests to the
Cache Manager API. A remote attacker with access privileges could possibly
use this issue to cause Squid to consume resources, leading to a denial of
service. This issue was only addressed in Ubuntu 20.04 LTS, Ubuntu 20.10,
and Ubuntu 21.04. (CVE-2021-28652)

Joshua Rogers discovered that Squid incorrectly handled certain response
headers. A remote attacker could possibly use this issue to cause Squid to
crash, resulting in a denial of service. This issue was only affected
Ubuntu 20.04 LTS, Ubuntu 20.10, and Ubuntu 21.04. (CVE-2021-28662)

Joshua Rogers discovered that Squid incorrectly handled range request
processing. A remote attacker could possibly use this issue to cause Squid
to crash, resulting in a denial of service. (CVE-2021-31806,
CVE-2021-31807, CVE-2021-31808)

Joshua Rogers discovered that Squid incorrectly handled certain HTTP
responses. A remote attacker could possibly use this issue to cause Squid
to crash, resulting in a denial of service. (CVE-2021-33620)

Update instructions

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

Ubuntu 21.04
Ubuntu 20.10
Ubuntu 20.04
Ubuntu 18.04

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