A memory exhaustion bug has been discovered in libdns, which is used by ISC DHCP 4.2. Theoretically this could be exploited to cause memory exhaustion in ISC DHCP 4.2.
Posting date: 26 March 2013
4.2.0 -> 4.2.5. ISC DHCP versions prior to 4.2.0 (including 4.1-ESV) are not affected.
From adjacent networks
Exploitation of a memory exhaustion bug in libdns is theoretically possible in ISC DHCP 4.2, which uses the library from BIND 9 for Dynamic DNS.
Unlike vulnerabilities which can be exercised by a machine impersonating a malicious client, exploitation of this vulnerability is complex and requires either controlling a nameserver with whom the DHCP server process is communicating or successfully spoofing traffic to appear as such. These preconditions result in a CVSS severity of "Low", but operators using vulnerable versions of DHCP 4.2 are nevertheless recommended to upgrade to DHCP 4.2.5-P1, which prevents exploitation of the libdns library defect.
Servers which are targeted by a successful attack will exhaust all memory available to the server process, which is likely to crash the DHCP
server and may affect other processes running on the same
physical machine when system memory is exhausted.
CVSS Score: 4.9
CVSS Equation: (AV:N/AC:H/Au:S/C:N/I:N/A:C)
For more information on the Common Vulnerability Scoring System and to obtain your specific environmental score please visit: http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2&vector=(AV:N/AC:H/Au:S/C:N/I:N/A:C)
No known active exploits.
Solution: Upgrade to DHCP 4.2.5-P1
Document Revision History:
1.0 Phase One - Advance Notification, 18 March 2013
1.2 Phase Two & Three Notification, 25 March 2013
2.0 Public notification, 26 March 2013
Japanese Translation: [planned]
Spanish Translation: [planned]
German Translation: [planned]
Portugese Translation: [planned]
If you'd like more information on our Forum or product support please visit www.isc.org/support
Do you still have questions? Questions regarding this advisory should go to email@example.com
Note: ISC patches only currently supported versions. When possible we indicate EOL versions affected.
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
This Knowledge Base article https://kb.isc.org/article/AA-00880 is the complete and official security advisory document.
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.
© 2001-2016 Internet Systems ConsortiumPlease help us to improve the content of our knowledge base by letting us know below how we can improve this article. If you have a technical question or problem on which you'd like help, please don't submit it here as article feedback. For assistance with problems and questions for which you have not been able to find an answer in our Knowledge Base, we recommend searching our community mailing list archives and/or posting your question there (you will need to register there first for your posts to be accepted). The bind-users and the dhcp-users lists particularly have a long-standing and active membership.ISC relies on the financial support of the community to fund the development of its open source software products. If you would like to support future product evolution and maintenance as well having peace of mind knowing that our team of experts are poised to provide you with individual technical assistance whenever you call upon them, then please consider our Professional Subscription Support services - details can be found on our main website.