Discussion:
[squid-announce] [ADVISORY] SQUID-2018:4 Cross-Site Scripting issue in TLS error processing
Amos Jeffries
2018-10-28 16:09:09 UTC
Permalink
__________________________________________________________________

Squid Proxy Cache Security Update Advisory SQUID-2018:4
__________________________________________________________________

Advisory ID: SQUID-2018:4
Date: October 28, 2018
Summary: Cross-Site Scripting issue
in TLS error processing.
Affected versions: Squid 3.1.12.1 -> 3.1.23
Squid 3.2.0.4 -> 3.5.28
Squid 4.0 -> 4.3
Fixed in version: Squid 4.4
__________________________________________________________________

http://www.squid-cache.org/Advisories/SQUID-2018_4.txt
__________________________________________________________________

Problem Description:

Due to incorrect input handling, Squid is vulnerable to a
Cross-Site Scripting vulnerability when generating HTTPS response
messages about TLS errors.

__________________________________________________________________

Severity:

This problem allows a malicious HTTPS server to trigger error
page delivery to a client and also inject arbitrary HTML code
into the resulting error response.

This problem is limited to Squid built with TLS / SSL support.

__________________________________________________________________

Updated Packages:

This bug is fixed by Squid version 4.4.

In addition, patches addressing this problem for the stable
releases can be found in our patch archives:

Squid 3.5:
http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-f1657a9decc820f748fa3aff68168d3145258031.patch

Squid 4:
http://www.squid-cache.org/Versions/v4/changesets/squid-4-828245b90206602014ce057c3db39fb80fcc4b08.patch

If you are using a prepackaged version of Squid then please refer
to the package vendor for availability information on updated
packages.

__________________________________________________________________

Determining if your version is vulnerable:

All Squid-2.x and older are not vulnerable.

All Squid-3.0 and older version are not vulnerable.

All Squid-3.x versions up to and including 3.4.14 built with
--disable-ssl are not vulnerable.

All Squid-3.x versions up to and including 3.4.14 built without
--enable-ssl are not vulnerable.

All Squid-3.1.12.1 and later versions up to and including
Squid-3.1.23 built with --enable-ssl are vulnerable.

All Squid-3.2.0.4 and later versions up to and including
Squid-3.2.14 built with --enable-ssl are vulnerable.

All Squid-3.3 and later versions up to and including
Squid-3.3.14 built with --enable-ssl are vulnerable.

All Squid-3.4 and later versions up to and including
Squid-3.4.14 built with --enable-ssl are vulnerable.

All Squid-3.5 versions up to and including 3.5.28 built without
--with-openssl are not vulnerable.

All Squid-3.5 and later versions up to and including 3.5.28 built
with --with-openssl are vulnerable.

All Squid-4 versions built without --with-openssl are not
vulnerable.

All Squid-4 versions up to and including 4.3 built with
--with-openssl are vulnerable.

__________________________________________________________________

Workarounds:

Either;

Remove %D error page macro from ERR_SECURE_CONNECT_FAIL and any
custom error pages.

Or,

Build Squid-3.1 to 3.4.14 without "--enable-ssl"

Or,

Build Squid-3.5 or later without "--with-openssl"

__________________________________________________________________

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-***@lists.squid-cache.org mailing list is your
primary support point. For subscription details see
<http://www.squid-cache.org/Support/mailing-lists.html>.

For reporting of non-security bugs in the latest STABLE release
the squid bugzilla database should be used
<http://bugs.squid-cache.org/>.

For reporting of security sensitive bugs send an email to the
squid-***@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.

__________________________________________________________________

Credits:

This vulnerability was discovered by Nikolas Lohmann of eBlocker
GmbH.

Fixed by Christos Tsantilas on behalf of Measurement Factory.

__________________________________________________________________

Revision history:

2018-10-15 10:59:16 UTC Initial Report
2018-10-17 15:13:41 UTC Patches Released
2018-10-27 21:19:00 UTC Packages Released
__________________________________________________________________
END

Loading...