==================================================================== CERT-Renater Note d'Information No. 2016/VULN145 _____________________________________________________________________ DATE : 04/04/2016 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Systems running Squid version 3, 4 prior to 4.0.8, 3.5.16. ====================================================================== http://www.squid-cache.org/Advisories/SQUID-2016_3.txt http://www.squid-cache.org/Advisories/SQUID-2016_4.txt _____________________________________________________________________ __________________________________________________________________ Squid Proxy Cache Security Update Advisory SQUID-2016:3 __________________________________________________________________ Advisory ID: SQUID-2016:3 Date: April 02, 2016 Summary: Buffer overrun issue in pinger ICMPv6 processing. Affected versions: Squid 3.1.0 -> 3.5.15 Squid 4.0 -> 4.0.7 Fixed in version: Squid 4.0.8, 3.5.16 __________________________________________________________________ http://www.squid-cache.org/Advisories/SQUID-2016_3.txt http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3947 __________________________________________________________________ Problem Description: Due to a buffer overrun Squid pinger binary is vulnerable to denial of service or information leak attack when processing ICMPv6 packets. This bug also permits the server response to manipulate other ICMP and ICMPv6 queries processing to cause information leak. __________________________________________________________________ Severity: This bug allows any remote server to perform a denial of service attack on the Squid service by crashing the pinger. This may affect Squid HTTP routing decisions. In some configurations, sub-optimal routing decisions may result in serious service degradation or even transaction failures. If the system does not contain buffer-overrun protection leading to that crash this bug will instead allow attackers to leak arbitrary amounts of information from the heap into Squid log files. This is of higher importance than usual because the pinger process operates with root priviliges. __________________________________________________________________ Updated Packages: This bug is fixed by Squid version 3.5.15 and 4.0.8. In addition, patches addressing this problem for stable releases can be found in our patch archives: Squid 3.1: http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10495.patch Squid 3.2: http://www.squid-cache.org/Versions/v3/3.2/changesets/squid-3.2-11839.patch Squid 3.3: http://www.squid-cache.org/Versions/v3/3.3/changesets/squid-3.3-12694.patch Squid 3.4: http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13232.patch Squid 3.5: http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-14015.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 versions are not vulnerable to this problem. All Squid-3.0 versions are not vulnerable to this problem. All Squid built with --disable-icmp are not vulnerable to this problem. All Squid built with --disable-ipv6 are not vulnerable to this problem. All Squid-3.x configured with "pinger_enable off" in squid.conf are not vulnerable to this problem. Check the server running processes list to determine if the Squid service is running a "pinger" child process. All unpatched Squid-3 versions up to and including 3.5.15 running the pinger process are vulnerable to this problem. All unpatched Squid-4 versions up to and including 4.0.7 running the pinger process are vulnerable to this problem. __________________________________________________________________ Workaround: Disable the pinger process in squid.conf: pinger_enable off __________________________________________________________________ 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: The vulnerability was reported and fixed by Yuriy M. Kaminskiy. __________________________________________________________________ Revision history: 2016-02-21 23:42:28 GMT Initial Report 2016-03-28 22:52:58 GMT Patch Released __________________________________________________________________ _____________________________________________________________________ __________________________________________________________________ Squid Proxy Cache Security Update Advisory SQUID-2016:4 __________________________________________________________________ Advisory ID: SQUID-2016:4 Date: April 02, 2016 Summary: Denial of Service issue in HTTP Response processing. Affected versions: Squid 3.x -> 3.5.15 Squid 4.x -> 4.0.7 Fixed in version: Squid 4.0.8, 3.5.16 __________________________________________________________________ http://www.squid-cache.org/Advisories/SQUID-2016_4.txt http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-3948 __________________________________________________________________ Problem Description: Due to incorrect bounds checking Squid is vulnerable to a denial of service attack when processing HTTP responses. __________________________________________________________________ Severity: This problem allows a malicious client script and remote server delivering certain unusual HTTP response syntax to trigger a denial of service for all clients accessing the Squid service. __________________________________________________________________ Updated Packages: This bug is fixed by Squid version 3.5.16 and 4.0.8. In addition, a patch addressing this problem for the stable release can be found in our patch archives: Squid 3.5: http://www.squid-cache.org/Versions/v3/3.5/changesets/squid-3.5-14016.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 unpatched Squid-3.0 versions are vulnerable. All unpatched Squid-3.1 versions are vulnerable. All unpatched Squid-3.2 versions are vulnerable. All unpatched Squid-3.3 versions are vulnerable. All unpatched Squid-3.4 versions are vulnerable. All unpatched Squid-3.5 up to and including Squid-3.5.15 are vulnerable. All unpatched Squid-4.0 up to and including 4.0.7 are vulnerable. __________________________________________________________________ Workaround: There are no good workarounds known for this vulnerability. The following squid.conf settings can protect Squid-3.5 (only): acl Vary rep_header Vary . store_miss deny Vary Or, The following squid.conf setting can protect Squid-3.0 or later: cache deny all __________________________________________________________________ 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 reported by Santiago R. Rincon of Debian. Fixed by Amos Jeffries from Treehouse Networks Ltd. __________________________________________________________________ Revision history: 2016-03-20 11:25:04 UTC Initial Report 2016-04-01 06:15:31 UTC Patch Released __________________________________________________________________ ========================================================== Serveur de référence du CERT-Renater https://services.renater.fr/ssi/ ========================================================== + CERT-RENATER | tel : 01-53-94-20-44 + + 23 - 25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email: cert@support.renater.fr + ==========================================================