[squid-users] [squid-announce] [ADVISORY] SQUID-2019:4 Multiple Issues in HTTP Request processing

Amos Jeffries squid3 at treenet.co.nz
Sat Apr 18 13:10:00 UTC 2020


    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


Problem Description:

 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.


Updated Packages:

 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:

Squid 4:

 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
 not vulnerable.

 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
 package vendor.

 If your install and build Squid from the original Squid sources
 then the squid-users at lists.squid-cache.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
 squid-bugs at lists.squid-cache.org 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
 <jeriko.one at gmx.us>.

 Fixed by Amos Jeffries of Treehouse Networks Ltd.


Revision history:

 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
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