__________________________________________________________________ Squid Proxy Cache Security Update Advisory SQUID-2014:3 __________________________________________________________________ Advisory ID: SQUID-2014:3 Date: September 15, 2014 Summary: Buffer overflow in SNMP processing Affected versions: Squid 3.x -> 3.4.7 Fixed in version: Squid 3.4.8 __________________________________________________________________ http://www.squid-cache.org/Advisories/SQUID-2014_3.txt http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-6270 __________________________________________________________________ Problem Description: Due to incorrect buffer management Squid can be caused by an attacker to write outside its allocated SNMP buffer. __________________________________________________________________ Severity: The bug is important because it allows remote attackers to crash Squid, causing a disruption in service. However, the bug is exploitable only if you have configured Squid to receive SNMP messages. Sites that do not use SNMP are not vulnerable. __________________________________________________________________ Updated Packages: This bug is fixed by Squid version 3.4.8 In addition, patches addressing this problem for stable releases can be found in our patch archives: Squid 3.0: http://www.squid-cache.org/Versions/v3/3.0/changesets/squid-3.0-9202.patch Squid 3.1: http://www.squid-cache.org/Versions/v3/3.1/changesets/squid-3.1-10489.patch Squid 3.2: http://www.squid-cache.org/Versions/v3/3.2/changesets/squid-3.2-11829.patch Squid 3.3: http://www.squid-cache.org/Versions/v3/3.3/changesets/squid-3.3-12682.patch Squid 3.4: http://www.squid-cache.org/Versions/v3/3.4/changesets/squid-3.4-13172.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 built with --disable-snmp are not vulnerable to the problem. All Squid operating with "snmp_port 0" in squid.conf are not vulnerable to the problem. All Squid-3.x operating with snmp_port omitted from squid.conf are not vulnerable to the problem. All Squid-2.x operating with snmp_port omitted from squid.conf are vulnerable to the problem. All unpatched Squid versions up to and including 3.4.7 with snmp_port configured to a non-0 value are vulnerable to the problem. __________________________________________________________________ Workaround: Either, Configure the firewall controlling access to Squid service such that only specific trusted sources can deliver SNMP packets to the Squid SNMP listening port. Or, Disable SNMP. Which may be done in any of the following ways: * Build Squid with ./configure --disable-snmp * For Squid-2.x add the following directive to squid.conf file: snmp_port 0 * For Squid-3.x remove from squid.conf (and include'd files) any of the following directives which are present: snmp_port snmp_access snmp_incoming_address snmp_outgoing_address __________________________________________________________________ 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 you install and build Squid from the original Squid sources then the squid-users@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 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@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 discovered and fixed by Sebastian Krahmer of the OpenSUSE Project. __________________________________________________________________ Revision history: 2014-09-09 12:01 GMT Initial Report 2014-09-10 06:12 GMT CVE Assignment 2014-09-15 08:15 GMT Patches and Packages Released __________________________________________________________________ END