Multiple vendors' Internet Key Exchange (IKE) implementations do not properly handle IKE response packets

2002-08-12T00:00:00
ID VU:287771
Type cert
Reporter CERT
Modified 2004-02-09T00:00:00

Description

Overview

Internet Key Exchange (IKE) implementations from several vendors contain buffer overflows and denial-of-service conditions. The buffer overflow vulnerabilities could permit an attacker to execute arbitrary code on a vulnerable system.

Description

The CERT/CC has received a report describing several vulnerabilities in different vendors' IKE implementations. The IKE protocol (RFC 2409) operates within the framework of the Internet Security Association and Key Management Protocol (ISAKMP, RFC 2408) and provides a way for nodes to authenticate each other and exchange keying material that is used to establish secure network services. IKE is commonly used by IPSec-based VPNs.

During an IKE exchange, some IKE implementations do not properly handle exceptional response packets. The report enumerates several cases:

  • IKE represents the ISAKMP security association (SA) in the Security Paramater Index (SPI) field of a response packet. An overly large SPI payload value could trigger a buffer overflow.
  • An IKE response packet with a large number of payloads or an overly large payload could trigger buffer overflows.
  • An IKE response packet with a payload length of zero could cause vulnerable IKE implementations to consume CPU resources, causing a denial-of-service condition. These problems have been shown to exist in IPSec-based VPN client software operating in Aggressive Mode during a phase 1 IKE exchange. Other software and other types of exchanges may also be affected.

Impact

An attacker who is able to send solicited IKE responses could execute arbitrary code with the privileges of the IKE service or cause a denial of service. The attacker must act as an IKE responder, so therefore must have control over the responder, the ability to spoof IKE response packets, or the ability to redirect the IKE initiator to a responder controlled by the attacker.


Solution

Upgrade or Patch
Upgrade or apply a patch to vulnerable IKE software as specified by your vendor.


Block or Restrict Access

Using a firewall or other packet filtering technology, block or restrict access to the IKE service, 500/udp. Note that blocking access will effectively disable an IPSec-based VPN that relies on IKE for key exchange.


Systems Affected

Vendor| Status| Date Notified| Date Updated
---|---|---|---
Cisco Systems Inc.| | 08 May 2002| 09 Aug 2002
NetScreen| | -| 05 Feb 2003
Network Associates| | 08 May 2002| 10 Sep 2002
OpenBSD| | 02 Jul 2002| 05 Feb 2003
PGP| | 10 May 2002| 05 Sep 2002
SafeNet| | 13 May 2002| 20 Aug 2002
SonicWALL Inc.| | -| 01 Apr 2003
Apple Computer Inc.| | 02 Jul 2002| 06 Aug 2002
Clavister| | -| 05 Sep 2002
Cray Inc.| | 02 Jul 2002| 06 Aug 2002
FreeBSD| | 02 Jul 2002| 05 Sep 2002
Fujitsu| | 02 Jul 2002| 12 Aug 2002
Hewlett-Packard Company| | 02 Jul 2002| 05 Feb 2003
Hitachi| | -| 05 Sep 2002
IBM| | 02 Jul 2002| 11 Dec 2002
If you are a vendor and your product is affected, let us know.

CVSS Metrics

Group | Score | Vector
---|---|---
Base | N/A | N/A
Temporal | N/A | N/A
Environmental | N/A | N/A

References

  • <http://www.ietf.org/html.charters/ipsec-charter.html>
  • <http://www.ietf.org/rfc/rfc2408.txt>
  • <http://www.ietf.org/rfc/rfc2409.txt>
  • <http://www.ietf.org/rfc/rfc2412.txt>
  • <http://www.vpnc.org/>
  • <http://online.securityfocus.com/bid/5440>
  • <http://online.securityfocus.com/bid/5441>
  • <http://online.securityfocus.com/bid/5443>
  • <http://www.securityfocus.com/bid/5449>
  • <http://www.securityfocus.com/bid/5668>
  • <http://ikecrack.sourceforge.net/>
  • <http://www.nta-monitor.com/ike-scan/>

Credit

The CERT/CC thanks Anton Rager of Avaya Security Consulting Services from Avaya, Inc. for reporting this vulnerability and providing information used in this document.

This document was written by Art Manion.

Other Information

  • CVE IDs: Unknown
  • Date Public: 14 Aug 2002
  • Date First Published: 12 Aug 2002
  • Date Last Updated: 09 Feb 2004
  • Severity Metric: 1.03
  • Document Revision: 52