CVE-2021-34709 : Exploit Details and Defense Strategies

This article discusses multiple vulnerabilities in image verification checks of Cisco Network Convergence System (NCS) 540 Series Routers and Cisco IOS XR Software for Cisco 8000 Series Routers. An authenticated local attacker could exploit these vulnerabilities to execute arbitrary code on the operating system.

Understanding CVE-2021-34709

This CVE entry addresses security issues in Cisco IOS XR Software affecting Cisco 8000 and Network Convergence System 540 Series Routers.

What is CVE-2021-34709?

The CVE-2021-34709 vulnerability involves image verification checks in Cisco NCS 540 Series Routers and Cisco IOS XR Software for Cisco 8000 Routers, allowing a local attacker to run arbitrary code on the system.

The Impact of CVE-2021-34709

This vulnerability has a CVSSv3.1 base score of 6.0 (Medium Severity). It requires high privileges for exploitation and can lead to high confidentiality and integrity impact on affected systems.

Technical Details of CVE-2021-34709

This section provides technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows an authenticated local attacker to execute arbitrary code on the underlying OS through image verification checks.

Affected Systems and Versions

Product: Cisco IOS XR Software
Versions: n/a

Exploitation Mechanism

The attacker needs local access to the targeted system to exploit this vulnerability.

Mitigation and Prevention

To protect your systems from CVE-2021-34709, consider the following measures.

Immediate Steps to Take

Restrict physical access to the affected devices.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Keep software up to date with the latest security patches.
Implement strict access control policies.

Patching and Updates

Apply the patches provided by Cisco to address the vulnerabilities in the affected software versions.