When the DHCPv6 server code processes a message for an address that was previously declined and internally tagged as abandoned it can trigger an assert failure resulting in the server crashing. This could be used to crash DHCPv6 servers remotely. This issue only affects DHCPv6 servers. DHCPv4 servers are unaffected.
CVSS Score: 6.1 (AV:A/AC:L/Au:N/C:N/I:N/A:C)
For more information on CVSS scores, visit http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2
There is no direct workaround.
Exposure to the vulnerability can be limited by a review of the filters and access to the DHCP server. It is highly recommended to limit access to those devices which require DHCP server, management access, and systems monitoring.
Upgrade to 4.1.2-P1, 4.1-ESV-R1, or 4.2.1b1
Do you have Questions? Questions regarding this advisory should go to security-officer@isc.org.
This security advisory is a copy of the official document located on our website: https://www.isc.org/software/dhcp/advisories/cve-2011-0413
Do you need Software Support? Questions on ISC's Support services or other offerings should be sent to sales@isc.org. More information on ISC's support and other offerings are available at: http://www.isc.org/community/blog/201102/BIND-support
ISC Security Vulnerability Disclosure Policy: Details of our current security advisory policy and practice can be found here: https://www.isc.org/security-vulnerability-disclosure-policy
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.
