__________________________________________________________________ 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-users@xxxxxxxxxxxxxxxxxxxxx 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-bugs@xxxxxxxxxxxxxxxxxxxxx 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 _______________________________________________ squid-announce mailing list squid-announce@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-announce