__________________________________________________________________ Squid Proxy Cache Security Update Advisory SQUID-2019:3 __________________________________________________________________ Advisory ID: SQUID-2019:3 Date: July 12, 2019 Summary: Denial of Service issue in HTTP Digest Authentication processing. Affected versions: Squid 3.3.9 -> 3.5.28 Squid 4.x -> 4.7 Fixed in version: Squid 4.8 __________________________________________________________________ http://www.squid-cache.org/Advisories/SQUID-2019_3.txt http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-12525 __________________________________________________________________ Problem Description: Due to incorrect buffer management Squid is vulnerable to a denial of service attack when processing HTTP Digest Authentication credentials. __________________________________________________________________ Severity: Due to incorrect input validation the HTTP Request header parser for Digest authentication may access memory outside the allocated memory buffer. On systems with memory access protections this can result in the Squid process being terminated unexpectedly. Resulting in a denial of service for all clients using the proxy. __________________________________________________________________ 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 3.5: Squid 4: 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 are not vulnerable. All Squid-3.x up to and including 3.3.8 are not vulnerable. All Squid-3.3.9 up to and including 3.3.14 being used for Digest authentication are vulnerable. All Squid-3.4 versions up to and including 3.4.14 being used for Digest authentication are vulnerable. All Squid-3.5 versions up to and including 3.5.28 being used for Digest authentication are vulnerable. All Squid-4.x up to and including 4.7 being used for Digest Authentication are vulnerable. To determine whether auth_param is configured for Digest authentication use the command: squid -k parse | grep auth_param __________________________________________________________________ Workarounds: Either; Remove 'auth_param digest ...' configuration settings from squid.conf. Or, Build Squid with --disable-auth-digest __________________________________________________________________ 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@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@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 Jeriko One . Fixed by Amos Jeffries of Treehouse Networks Ltd. __________________________________________________________________ Revision history: 2019-05-14 14:56:49 UTC Initial Report 2019-06-05 15:52:17 UTC CVE Assignment 2019-06-08 21:09:23 UTC Patches Released 2019-07-12 13:00:00 UTC Advisory Released __________________________________________________________________ END