While we are posting it in this public announcement forum (as is our process for handling all security vulnerabilities in BIND) please note that the following security advisory applies ONLY to several releases in BIND 9 Supported Preview Edition, a special feature preview version of BIND that is provided to eligible ISC support customers but not released publicly.
Unless you are running a version of BIND that is built from a Supported Preview Edition release this vulnerability disclosure should not apply to you and may be safely disregarded. If you are uncertain what version of BIND you are running -- all modern versions of BIND should report their version and build info if you invoke the server with the "-V" argument, i.e. "named -V" If your version information does not match one of the release versions listed in the "Versions affected" field below then you are not affected. ---- CVE: CVE-2018-5734 Document Version: 2.0 Posting date: 28 Feb 2018 Program Impacted: BIND Versions affected: 9.10.5-S1 to 9.10.5-S4, 9.10.6-S1, 9.10.6-S2 Severity: High Exploitable: Remotely Description: While handling a particular type of malformed packet BIND erroneously selects a SERVFAIL rcode instead of a FORMERR rcode. If the receiving view has the SERVFAIL cache feature enabled, this can trigger an assertion failure in badcache.c when the request doesn't contain all of the expected information. Impact: Servers running the affected versions (9.10.5-S1 to 9.10.5-S4, 9.10.6-S1, and 9.10.6-S2) are vulnerable if they allow recursion, unless the SERVFAIL cache is disabled for the receiving view. CVSS Score: 7.5 CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Workarounds: Disabling the SERVFAIL cache with 'servfail-ttl 0;' will prevent taking the code path that leads to the assertion failure. Active exploits: No known active exploits. Solution: Upgrade to the patched release. No publicly released versions of BIND are affected BIND Supported Preview Edition is a special feature preview branch of BIND provided to eligible ISC support customers. - BIND 9 version 9.10.6-S3 Document Revision History: 1.0 Advance Notification 20 February, 2018 2.0 Public Disclosure 28 February, 2018 Related Documents: See our BIND9 Security Vulnerability Matrix at https://kb.isc.org/article/AA-00913 for a complete listing of Security Vulnerabilities and versions affected. If you'd like more information on ISC Subscription Support and Advance Security Notifications, please visit http://www.isc.org/support/. Do you still have questions? Questions regarding this advisory should go to security-offi...@isc.org. To report a new issue, please encrypt your message using security-offi...@isc.org's PGP key which can be found here: https://www.isc.org/downloads/software-support-policy/openpgp-key/. If you are unable to use encrypted email, you may also report new issues at: https://www.isc.org/community/report-bug/. Note: ISC patches only currently supported versions. When possible we indicate EOL versions affected. (For current information on which versions are actively supported, please see http://www.isc.org/downloads/). ISC Security Vulnerability Disclosure Policy: Details of our current security advisory policy and practice can be found here: https://kb.isc.org/article/AA-00861 This Knowledge Base article https://kb.isc.org/article/AA-01562 is the complete and official security advisory document. Legal Disclaimer: Internet Systems Consortium (ISC) is providing this notice on an "AS IS" basis. No warranty or guarantee of any kind is expressed in this notice and none should be implied. ISC expressly excludes and disclaims any warranties regarding this notice or materials referred to in this notice, including, without limitation, any implied warranty of merchantability, fitness for a particular purpose, absence of hidden defects, or of non-infringement. Your use or reliance on this notice or materials referred to in this notice is at your own risk. ISC may change this notice at any time. A stand-alone copy or paraphrase of the text of this document that omits the document URL is an uncontrolled copy. Uncontrolled copies may lack important information, be out of date, or contain factual errors. (c) 2001-2018 Internet Systems Consortium _______________________________________________ bind-announce mailing list bind-announce@lists.isc.org https://lists.isc.org/mailman/listinfo/bind-announce
