A Squid security update has been released for Ubuntu Linux 18.04 LTS and 16.04 LTS.

USN-4551-1: Squid vulnerabilities

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Ubuntu Security Notice USN-4551-1
September 28, 2020

squid3 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Squid.

Software Description:
- squid3: Web proxy cache server

Details:

Alex Rousskov and Amit Klein discovered that Squid incorrectly handled
certain Content-Length headers. A remote attacker could possibly use this
issue to perform an HTTP request smuggling attack, resulting in cache
poisoning. (CVE-2020-15049)

Amit Klein discovered that Squid incorrectly validated certain data. A
remote attacker could possibly use this issue to perform an HTTP request
smuggling attack, resulting in cache poisoning. (CVE-2020-15810)

Régis Leroy discovered that Squid incorrectly validated certain data. A
remote attacker could possibly use this issue to perform an HTTP request
splitting attack, resulting in cache poisoning. (CVE-2020-15811)

Lubos Uhliarik discovered that Squid incorrectly handled certain Cache
Digest response messages sent by trusted peers. A remote attacker could
possibly use this issue to cause Squid to consume resources, resulting in a
denial of service. (CVE-2020-24606)

Update instructions:

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

Ubuntu 18.04 LTS:
squid 3.5.27-1ubuntu1.9

Ubuntu 16.04 LTS:
squid 3.5.12-1ubuntu7.15

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

References:
  https://usn.ubuntu.com/4551-1
CVE-2020-15049, CVE-2020-15810, CVE-2020-15811, CVE-2020-24606

Package Information:
  https://launchpad.net/ubuntu/+source/squid3/3.5.27-1ubuntu1.9
  https://launchpad.net/ubuntu/+source/squid3/3.5.12-1ubuntu7.15