CVE-2017-6610 : What You Need to Know

A weakness discovered in the code of Cisco ASA Software's Internet Key Exchange Version 1 (IKEv1) XAUTH feature allows a remote attacker who is authenticated to cause a system reload. The vulnerability arises from inadequate validation of the parameters associated with IKEv1 XAUTH during a negotiation. This vulnerability specifically impacts systems that are set up in either routed firewall mode or single/multiple context mode. Both IPv4 and IPv6 traffic can trigger this vulnerability. To exploit it, the attacker must establish a valid IKEv1 Phase 1, which requires knowledge of a pre-shared key or possession of a valid certificate for phase 1 authentication.

Understanding CVE-2017-6610

This CVE identifies a vulnerability in Cisco ASA Software that can be exploited by a remote authenticated attacker to trigger a system reload.

What is CVE-2017-6610?

The vulnerability in the Internet Key Exchange Version 1 (IKEv1) XAUTH code of Cisco ASA Software allows an authenticated remote attacker to cause a reload of an affected system due to insufficient validation of IKEv1 XAUTH parameters during negotiation. Only traffic directed to the affected system can be used for exploitation.

The Impact of CVE-2017-6610

An authenticated remote attacker can cause a system reload by exploiting the vulnerability in Cisco ASA Software's IKEv1 XAUTH feature.
Systems configured in routed firewall mode or single/multiple context mode are specifically affected.
Both IPv4 and IPv6 traffic can trigger this vulnerability.

Technical Details of CVE-2017-6610

The technical aspects of the vulnerability in Cisco ASA Software.

Vulnerability Description

The vulnerability is due to insufficient validation of IKEv1 XAUTH parameters during negotiation.
Exploitation requires establishing a valid IKEv1 Phase 1, necessitating knowledge of a pre-shared key or possession of a valid certificate.

Affected Systems and Versions

Systems configured in routed firewall mode or single/multiple context mode are impacted.
Products affected include Cisco ASA 1000V Cloud Firewall, Cisco ASA 5500 Series Adaptive Security Appliances, Cisco ASA 5500-X Series Next-Generation Firewalls, and more.

Exploitation Mechanism

Exploitation involves sending carefully crafted parameters to trigger the vulnerability.
Only traffic directed to the affected system can be utilized for exploitation.

Mitigation and Prevention

Steps to mitigate and prevent the exploitation of CVE-2017-6610.

Immediate Steps to Take

Apply the fixed versions of the software: 9.1(7.7), 9.2(4.11), 9.4(4), 9.5(3), and 9.6(1.5).
Monitor and restrict traffic to the affected systems.

Long-Term Security Practices

Regularly update and patch Cisco ASA Software to the latest versions.
Implement strong authentication mechanisms for IKEv1 Phase 1.

Patching and Updates

Ensure timely installation of security patches provided by Cisco to address the vulnerability.