--- title: "CVE-2015-8373: ISC Kea: unexpected termination while handling a malformed packet" slug: "aa-01318" description: "CVE-2015-8373 - ISC Kea: unexpected termination while handling a malformed packet" tags: ["kea dhcp"] updated: 2018-11-16T20:01:14Z published: 2018-11-16T20:01:14Z canonical: "kb.isc.org/aa-01318" --- > ## 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-2015-8373: ISC Kea: unexpected termination while handling a malformed packet ISC Kea may terminate unexpectedly (crash) while handling a malformed client packet. **CVE:** [CVE-2015-8373](http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8373) **Document version:** 2.0 **Posting date:** 22 December 2015 **Program impacted:** [ISC Kea](https://www.isc.org/kea) **Versions affected:** 0.9.2, 1.0.0-beta **Severity:** Critical **Exploitable:** Remotely **Description:** 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. **Impact:** 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: [http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2&vector=(AV:N/AC:M/Au:N/C:N/I:N/A:C)](http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2&vector=(AV:N/AC:M/Au:N/C:N/I:N/A:C)). **Workarounds:** 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 [https://www.isc.org/downloads](https://www.isc.org/downloads). - 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 1.0.0-beta) 1.2 Revised, 21 December 2015 (DHCPv4 workarounds determined and added) 2.0 Public Disclosure, 22 December 2015 **Related documents:** If you'd like more information on ISC Subscription Support and Advance Security Notifications, please visit [https://www.isc.org/support/](https://www.isc.org/support). **Do you still have questions?** Questions regarding this advisory should go to [security-officer@isc.org](mailto:security-officer@isc.org). *To report a new issue, please encrypt your message using security-officer@isc.org's PGP key which can be found here: [https://www.isc.org/downloads/software-support-policy/openpgp-key/](https://www.isc.org/downloads/software-support-policy/openpgp-key). If you are unable to use encrypted email, you may also report new issues at: [https://www.isc.org/community/report-bug/](https://www.isc.org/community/report-bug).* **Note:** ISC patches only currently supported versions. When possible, we indicate EOL versions affected. (For current information on which versions are actively supported, please see [https://www.isc.org/downloads/](https://www.isc.org/downloads).) **ISC Security Vulnerability Disclosure Policy:** Details of our current security advisory policy and practice can be found in the [ISC Software Defect and Security Vulnerability Disclosure Policy](https://kb.isc.org/docs/aa-00861). This [Knowledgebase article](https://kb.isc.org/docs/aa-01318) is the complete and official security advisory document. **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. 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