Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2015.3183 BIND remote denial of service vulnerability 21 December 2015 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: bind Publisher: FreeBSD Operating System: FreeBSD Impact/Access: Denial of Service -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2015-8000 Reference: ESB-2015.3145 Original Bulletin: ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-15:27.bind.asc - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 ============================================================================= FreeBSD-SA-15:27.bind Security Advisory The FreeBSD Project Topic: BIND remote denial of service vulnerability Category: contrib Module: bind Announced: 2015-12-16 Credits: ISC Affects: FreeBSD 9.x Corrected: 2015-12-16 06:10:05 UTC (stable/9, 9.3-STABLE) 2015-12-16 06:21:26 UTC (releng/9.3, 9.3-RELEASE-p32) CVE Name: CVE-2015-8000 For general information regarding FreeBSD Security Advisories, including descriptions of the fields above, security branches, and the following sections, please visit <URL:https://security.FreeBSD.org/>. I. Background BIND 9 is an implementation of the Domain Name System (DNS) protocols. The named(8) daemon is an Internet Domain Name Server. The libdns library is a library of DNS protocol support functions. II. Problem Description An error in the parsing of incoming responses allows some records with an incorrect class to be be accepted by BIND instead of being rejected as malformed. This can trigger a REQUIRE assertion failure when those records are subsequently cached. III. Impact An attacker who can cause a server to request a record with a malformed class attribute can use this bug to trigger a REQUIRE assertion in db.c, causing named to exit and denying service to clients. The risk to recursive servers is high. Authoritative servers are at limited risk if they perform authentication when making recursive queries to resolve addresses for servers listed in NS RRSETs. IV. Workaround No workaround is available, but hosts not running named(8) are not vulnerable. V. Solution Perform one of the following: 1) Upgrade your vulnerable system to a supported FreeBSD stable or release / security branch (releng) dated after the correction date. The named service has to be restarted after the update. A reboot is recommended but not required. 2) To update your vulnerable system via a binary patch: Systems running a RELEASE version of FreeBSD on the i386 or amd64 platforms can be updated via the freebsd-update(8) utility: # freebsd-update fetch # freebsd-update install The named service has to be restarted after the update. A reboot is recommended but not required. 3) To update your vulnerable system via a source code patch: The following patches have been verified to apply to the applicable FreeBSD release branches. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. [FreeBSD 9.3] # fetch https://security.FreeBSD.org/patches/SA-15:27/bind.patch # fetch https://security.FreeBSD.org/patches/SA-15:27/bind.patch.asc # gpg --verify bind.patch.asc b) Apply the patch. Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system using buildworld and installworld as described in <URL:https://www.FreeBSD.org/handbook/makeworld.html>. Restart the applicable daemons, or reboot the system. VI. Correction details The following list contains the correction revision numbers for each affected branch. Branch/path Revision - - ------------------------------------------------------------------------- stable/9/ r292320 releng/9.3/ r292321 - - ------------------------------------------------------------------------- To see which files were modified by a particular revision, run the following command, replacing NNNNNN with the revision number, on a machine with Subversion installed: # svn diff -cNNNNNN --summarize svn://svn.freebsd.org/base Or visit the following URL, replacing NNNNNN with the revision number: <URL:https://svnweb.freebsd.org/base?view=revision&revision=NNNNNN> VII. References <URL:https://kb.isc.org/article/AA-01317> <URL:https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8000> The latest revision of this advisory is available at <URL:https://security.FreeBSD.org/advisories/FreeBSD-SA-15:27.bind.asc> - -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.1.8 (FreeBSD) iQIcBAEBCgAGBQJWcQOeAAoJEO1n7NZdz2rnpUoQAIjWIowpcRnteiQ8xJFnebHN iXj0vEWBGXofefDF1QzMZe0+mu688Brw1UGC89alhJVKfcmUP66okW5KP+4KDWUp +jkIqjw0VLrWztc8V+YzGKkbFNprvYUKhzJJ/Y5TLjadqGRc5BBBDxwzY+9CnDfC P+OzaTHwO2HIrqclt5nVyhgBTXSGZHai6Eyw2fBuhmEqbOWNr4cBu8IVhAtvw6SR 0lFSSITZ2z6YrDTq7l7fkeJwv+MnerpBXfe57P6r6tbDzzmsmZiNKABsk9wW2lkP kuOTf14VNoMySCwQ60PUEtflERCTJ/QRZxZTbBRh4YZXJxPsERwj3dlfguMA/5Pq sO9cxbhSKdoaiswKev67uVUkJXCePb8YIfcxui9Wj5YgcYaN5Au9F/tX2xMmWwfp 2+XwiRkLoNao+NYrx6hAJjWxAUTZJJJhWvu6L7mpBiImsqczd5AJq52bqD/C2M5C v0acQ6ozNz2Fdkxy4YA1kuXm1STwFuCAfWSVYOpaLz42PeRrHzfqXFuAsoJCp8k1 2m2pFgLgQKGhje6XY9rtaFPLulGFDOem8tdYDHH94lgToinVIZ/+GcMbV4My7vr/ gWRnbzxr8J8/kdhUSp2+rlwnpdPEhgfcnxzwwr9F6duuwb5lLYCqNH/N4SOxRIAV En2VQ4vrDSCP7rszpvI7 =89Kp - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBVneWs36ZAP0PgtI9AQJEGA//VtYQy6mjkohxLQ+w8sMjYn1bN8gdc/Wx izg2QuYX8jzm3Sjc6Wc27p1BE7251h/dj8pF1w4WB5DGbH/A88QFogIChsUt3gSC /dtzRuhtcAR3yB1gHfakeRg6lWs2X62BYYSmdqSdmADxk2rInHIiYBVcvaiO7GlS TGkQ0ISWZlWfJGLtBx5j6glj/CliwCEg4jskEZD1mgyP3VW/Zct6lqSb3K3Rij1Z 18HewtEIEDraE/kRdw9RlCMnnXk9Gw9z1Ae9etyhD/zqp/iX+poVZFLwuZdzkNtR N2hdv3ORMLQ/zX8Y78r4n7yMYcmfxM8GMrkEPloyNhGeK06x4QPfOh0JbqBok5JN WiBEnKXkzZaCm03Q0vzY1ICfYe1HWVFRm7BqFOHxXnyjd+GjmQRWvENSjHmKC1wa 3gLClgsLeH+nT/HpBZUEEUpBUNO/aVufByJio611lI/UWDHwtOB8dyD34NsdEZRJ 5L8zCIAhnT9VobARrxdGpuHuFhObwF1gbN35HdYMI9rWD9pJjmPOgPMD7mt+qQhA yr9c5b1L3eG8CzwwNUlDEkoB80IVp41lxpFg56S/GpirJaN9iCOUwWzT/1JeNFKw /ukx0NWJdAIBVyRsjZtaI5vXVEHHgpESGRNaxMYif29+iY1GiJAafYAnGuE+ZmzH GV3qAd2Dj6U= =j9AS -----END PGP SIGNATURE-----