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             AUSCERT External Security Bulletin Redistribution

           CVE-2015-8373 - ISC Kea: unexpected termination while
                        handling a malformed packet
                             23 December 2015


        AusCERT Security Bulletin Summary

Product:           ISC Kea
Publisher:         ISC
Operating System:  UNIX variants (UNIX, Linux, OSX)
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2015-8373  

Original Bulletin: 

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CVE-2015-8373 - ISC Kea: unexpected termination while handling a malformed

Author:				ISC
Support Reference Number:	AA-01318
Views:				234
Created:			2015-11-30 17:17
Last Updated:			2015-12-22 22:16
0 Rating/ Voters

ISC Kea may terminate unexpectedly (crash) while handling a malformed
client packet.
CVE:			CVE-2015-8373
Document Version:	2.0
Posting date:		22 December 2015
Program Impacted:	ISC Kea
Versions affected:	0.9.2, 1.0.0-beta
Severity:		Critical
Exploitable:		Remotely


Related defects in the kea-dhcp4 and kea-dhcp6 servers can cause the server
to crash during option processing if a client sends a malformed packet.

    The kea-dhcp4 server is vulnerable only in versions 0.9.2 and 1.0.0-beta,
    and furthermore only when logging at debug level 40 or higher.  Servers
    running kea-dhcp4 versions 0.9.1 or lower, and servers which are not
    logging or are logging at debug level 39 or below are not vulnerable.
    The kea-dhcp6 server is vulnerable only in versions 0.9.2 and 1.0.0-beta,
    and furthermore only when logging at debug level 45 or higher.  Servers
    running kea-dhcp6 versions 0.9.1 or lower, and servers which are not
    logging or are logging at debug level 44 or below are not vulnerable.


An attacker sending a crafted malformed packet can cause an ISC Kea server
providing DHCP services to IPv4 or IPv6 clients to exit unexpectedly.

CVSS Score:  7.1

CVSS Vector:  (AV:N/AC:M/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:


For DHCPv4 services, disabling debug logging or logging at debug levels
of 39 or lower will protect ISC Kea against this vulnerability.

For DHCPv6 services, disabling debug logging or logging at debug levels
of 44 or lower will protect ISC Kea against this vulnerability.

Active exploits:

No known active exploits exist; this vulnerability was found during
internal testing.

Solution:  Upgrade to the patched release most closely related to
your current version of ISC Kea.  These can all be downloaded from

    ISC Kea version 0.9.2-P1
    ISC Kea version 1.0.0-beta2

Document Revision History:

1.0 Advance Notification 15 December 2015
1.1 Revised 18 December 2015 (limiting vulnerable versions to 0.9.2 and
1.2 Revised 21 December 2015 (DHCPv4 workarounds determined and added)
2.0 Public Disclosure, 22 December 2015

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