CVE-2019-1910 : What You Need to Know

Cisco IOS XR Software Intermediate System to Intermediate System Denial of Service Vulnerability

Understanding CVE-2019-1910

A vulnerability in Cisco IOS XR Software allows an unauthenticated attacker to exploit the IS-IS routing protocol, causing a denial of service (DoS) situation.

What is CVE-2019-1910?

The flaw in Cisco IOS XR Software enables an attacker within the same IS-IS area to send crafted IS-IS link-state protocol data units, triggering a DoS scenario by restarting the IS-IS process on vulnerable systems.

The Impact of CVE-2019-1910

Attack Complexity: Low
Attack Vector: Adjacent Network
Availability Impact: High
Base Score: 7.4 (High Severity)
Scope: Changed
No Confidentiality or Integrity Impact
No Privileges Required
No User Interaction

Technical Details of CVE-2019-1910

The vulnerability affects Cisco devices running older versions of IOS XR Software configured with the IS-IS routing protocol.

Vulnerability Description

Incorrect processing of crafted IS-IS link-state protocol data units

Affected Systems and Versions

Product: Cisco IOS XR Software
Vendor: Cisco
Versions Affected: < 6.6.3

Exploitation Mechanism

Attacker sends a specially crafted link-state PDU to vulnerable systems
Exploits the flaw to force routers to restart IS-IS process, leading to a DoS scenario

Mitigation and Prevention

Immediate Steps to Take:

Update affected systems to Cisco IOS XR Software Release 6.6.3 or later
Implement network segmentation to limit attacker access

Long-Term Security Practices:

Regularly monitor and patch network devices
Conduct security assessments to identify vulnerabilities

Patching and Updates:

Apply patches provided by Cisco to address the vulnerability