CVE-2017-12231 Explained : Impact and Mitigation

A vulnerability in the implementation of Network Address Translation (NAT) functionality in Cisco IOS versions 12.4 through 15.6 could allow an unauthenticated remote attacker to trigger a denial of service (DoS) scenario on affected devices. The flaw is related to the incorrect translation of H.323 messages using the Registration, Admission, and Status (RAS) protocol transmitted via IPv4 packets.

Understanding CVE-2017-12231

This CVE entry describes a vulnerability in Cisco IOS that could be exploited by an unauthorized remote individual to cause a DoS situation on targeted devices.

What is CVE-2017-12231?

The vulnerability in Cisco IOS versions 12.4 through 15.6 allows an attacker to send specially crafted H.323 RAS packets through affected devices, potentially leading to crashes and reloads, resulting in a DoS condition.

The Impact of CVE-2017-12231

An unauthorized remote attacker could exploit this vulnerability to trigger a DoS scenario on affected devices.
The flaw affects Cisco devices configured to use a NAT Application Layer Gateway (ALG) for H.323 RAS messages.

Technical Details of CVE-2017-12231

This section provides detailed technical information about the vulnerability.

Vulnerability Description

The vulnerability is caused by the incorrect translation of H.323 messages using the RAS protocol transmitted via IPv4 packets.

Affected Systems and Versions

Product: Cisco IOS
Versions: 12.4 through 15.6

Exploitation Mechanism

Attackers can exploit the vulnerability by sending specially crafted H.323 RAS packets through affected devices.
Successful exploitation can lead to device crashes and subsequent reloads, resulting in a DoS scenario.

Mitigation and Prevention

Protecting systems from CVE-2017-12231 requires immediate steps and long-term security practices.

Immediate Steps to Take

Disable NAT ALG for H.323 RAS messages if not required.
Implement network segmentation to limit the impact of potential attacks.

Long-Term Security Practices

Regularly update and patch Cisco IOS devices to mitigate known vulnerabilities.
Monitor network traffic for any suspicious activity that could indicate exploitation attempts.
Conduct security training for staff to increase awareness of potential threats.
Implement access controls and strong authentication mechanisms to prevent unauthorized access.

Patching and Updates

Apply patches provided by Cisco to address the vulnerability and enhance system security.