--- title: "CVE-2011-2748: ISC DHCP Server Halt" slug: "aa-00454" description: "CVE-2011-2748: ISC DHCP Server Halt" tags: ["isc dhcp"] updated: 2012-06-08T08:36:00Z published: 2012-06-08T08:36:00Z canonical: "kb.isc.org/aa-00454" --- > ## Documentation Index > Fetch the complete documentation index at: https://kb.isc.org/llms.txt > Use this file to discover all available pages before exploring further. # CVE-2011-2748: ISC DHCP Server Halt ## ISC DHCP Server Halt Two issues have been found in DHCP that could allow an attacker to cause the server to halt. CVE: [CVE-2011-2748](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-2748) Document Version: 1.1 Posting date: 10 Aug 2011 Program Impacted: [DHCP](http://www.isc.org/software/dhcp) Versions affected: 3.1.0 through 3.1-ESV-R1 (R2 never released) 4.0 all versions (EOL) 4.1.0 through 4.1.2rc1 4.1-ESV through 4.1-ESV-R3b1 4.2.0 through 4.2.2rc1 All End-of-Life versions of DHCP server are likely to be affected and ISC recommends upgrading to supported versions. Severity: High Exploitable: Remotely Description: A pair of defects cause the server to halt upon processing certain packets. The patch is to properly discard or process those packets. **Document ID:** CVE-2011-2748, CVE-2011-2749 **CVSS Score:** 7.8 **CVSS Equation:** (AV:N/AC:L/Au:N/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/cvww.cfm?calculator&adv&version=vector=(AV:N/AC:L/Au:N/C:N/I:N/A:C)](http://nvd.nist.gov/cvww.cfm?calculator&adv&version=vector=(AV:N/AC:L/Au:N/C:N/I:N/A:C)) Workarounds: Limiting DHCP and Bootp packets to only within your administrative domain will limit exposure. Active exploits: ISC received a report for one of the flaws and discovered the other during testing. No public exploits using these bugs are known. Solution: Upgrade to: 3.1-ESV-R3, 4.1-ESV-R3 or 4.2.2 Please note that this is the last update to 3.1-ESV as it will be End-of-Life after this release. Download these versions from [https://www.isc.org/downloads/all](https://www.isc.org/downloads/all) **Acknowledgment:** Found by David Zych at University of Illinois **Document Revision History** 1.0 27 July 2011 - Phase 1 disclosure 1.1 09 August 2011 - Phase 2 and 3 disclosures Releated Document: **References:** - 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](https://www.isc.org/security-vulnerability-disclosure-policy) **Do you have Questions?** Questions regarding this advisory should go to [security-officer@isc.org](mailto: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-2011-2748](https://www.isc.org/software/dhcp/advisories/cve-2011-2748) **Do you need Software Support?** Questions on ISC's Support services or other offerings should be sent to [sales@isc.org](mailto:sales@isc.org). More information on ISC's support and other offerings are available at: [http://www.isc.org/community/blog/201102/BIND-support](http://www.isc.org/community/blog/201102/BIND-support) 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. 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