It was found that Squid, a high-performance proxy caching server for web clients, has been affected by multiple security vulnerabilities. Due to incorrect input validation and URL request handling it was possible to bypass access restrictions for restricted HTTP servers and to cause a denial-of-service.

For Debian 9 stretch, these problems have been fixed in version 3.5.23-5+deb9u2.

We recommend that you upgrade your squid3 packages.

For the detailed security status of squid3 please refer to its security tracker page at: https://security-tracker.debian.org/tracker/squid3

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS