ISC Security Advisory: An Error in the Handling of an Unexpected Client Identifiers can Cause Server Crash When Serving DHCPv6

Cathy Almond cathya at
Tue Jul 24 17:54:40 UTC 2012

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Title:  An error in the handling of an unexpected client identifiers can
cause a server crash when serving DHCPv6.
CVE:                       CVE-2012-3570
Document Version:          2.0
Posting date:              24 Jul 2012
Program Impacted:          DHCP
Versions affected:         4.2.0 --> 4.2.4
Severity:                  High
Exploitable:          From adjacent networks


An unexpected client identifier parameter can cause the ISC DHCP daemon
to segmentation fault when running in DHCPv6 mode, resulting in a denial
of service to further client requests.

In order to exploit this condition, an attacker must be able to send
requests to the DHCP server.


Causes the server process to crash when a buffer overflows, resulting in
a denial of service.  NOTE: DHCP versions 4.0 -->4.1.x are NOT impacted.

CVSS Score: 6.1

CVSS Equation:  (AV:A/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

Active exploits:

None known at this time.

Upgrade affected systems to DHCP 4.2.4-P1

DHCP 4.2.4-P1 is available from

Markus Hietava of Codenomicon CROSS project for finding the
vulnerability, and CERT-FI for vulnerability coordination.

Document Revision History:

    1.0 - 03 July 2012 - Phase I notified
    1.1 - 13 July 2012 HOLD notice sent to Phase 1 regarding new CVE
being added and new public release date
    1.2 - 23 July 2012 Phase 2 & 3 notified
    2.0 - 24 July 2012 Phase 4-Public release


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