Squid Proxy Cache Security Update Advisory SQUID-2019:4
Advisory ID: SQUID-2019:4
Date: April 18, 2020
Summary: Multiple Issues
in HTTP Request processing.
Affected versions: Squid 3.5.18 -> 3.5.28
Squid 4.0.10 -> 4.7
Fixed in version: Squid 4.8
Due to incorrect URL handling Squid is vulnerable to access
control bypass, cache poisoning and cross-site scripting attacks
when processing HTTP Request messages.
A remote client can deliver crafted URLs to bypass cache manager
security controls and retrieve confidential details about the
proxy and traffic it is handling.
A remote client can deliver crafted URLs which cause arbitrary
content from one origin server to be stored in cache as URLs
within another origin. This opens a window of opportunity for
clients to be tricked into fetching and XSS execution of that
content via side channels.
This bug is fixed by Squid version 4.8.
In addition, patches addressing this problem for the stable
releases can be found in our patch archives:
If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
Determining if your version is vulnerable:
All Squid-2.x are not vulnerable.
All Squid-3.x up to and including 3.5.17 are not vulnerable.
All Squid-3.5.18 up to and including 3.5.28 are vulnerable.
All Squid-4.x up to and including 4.0.9 are not vulnerable.
All Squid-4.x up to and including 4.7 without HTTPS support are
All Squid-4.0.10 up to and including 4.7 with HTTPS support are
There are no workarounds for Squid-3.5.
For Squid-4 build using --without-openssl --without-gnutls
Contact details for the Squid project:
For installation / upgrade support on binary packaged versions
of Squid: Your first point of contact should be your binary
If your install and build Squid from the original Squid sources
then the firstname.lastname@example.org mailing list is your
primary support point. For subscription details see
For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
For reporting of security sensitive bugs send an email to the
email@example.com mailing list. It's a closed
list (though anyone can post) and security related bug reports
are treated in confidence until the impact has been established.
This vulnerability was discovered by Jeriko One
Fixed by Amos Jeffries of Treehouse Networks Ltd.
2019-05-14 14:56:49 UTC Initial Report
2019-06-23 15:15:56 UTC Patches Released
2019-06-05 15:52:17 UTC CVE Assignment
squid-announce mailing list
Who is up for this one?
squid 4.8 was relased in July 2019.
we are already on a newer version.