USN-7804-2: Squid vulnerability

Publication date

4 November 2025

Overview

Squid could be made to crash if it received specially crafted network traffic.


Packages

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

Details

USN-7804-1 fixed a vulnerability in Squid. This update provides the
corresponding update for Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu
20.04 LTS.

Original advisory details:

It was discovered that Squid incorrectly handled certain long SNMP OIDs. A
remote attacker could possibly use this issue to cause Squid to crash,
resulting in a denial of service.

USN-7804-1 fixed a vulnerability in Squid. This update provides the
corresponding update for Ubuntu 16.04 LTS, Ubuntu 18.04 LTS and Ubuntu
20.04 LTS.

Original advisory details:

It was discovered that Squid incorrectly handled certain long SNMP OIDs. A
remote attacker could possibly use this issue to cause Squid to crash,
resulting in a denial of service.

Update instructions

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
20.04 LTS focal squid –  4.10-1ubuntu1.13+esm2  
18.04 LTS bionic squid –  3.5.27-1ubuntu1.14+esm5  
squid3 –  3.5.27-1ubuntu1.14+esm5  
16.04 LTS xenial squid –  3.5.12-1ubuntu7.16+esm6  
squid3 –  3.5.12-1ubuntu7.16+esm6  

Reduce your security exposure

Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.


Have additional questions?

Talk to a member of the team ›