CVE-2021-34991 Explained : Impact and Mitigation

This CVE article provides insights into CVE-2021-34991, a vulnerability affecting NETGEAR R6400v2 routers.

Understanding CVE-2021-34991

CVE-2021-34991 is a vulnerability that enables network-adjacent attackers to run arbitrary code on NETGEAR R6400v2 routers without authentication.

What is CVE-2021-34991?

This vulnerability in NETGEAR R6400v2 routers allows attackers to execute code without authentication by exploiting a flaw in the UPnP service's handling of user-supplied data. The flaw occurs due to inadequate validation of the length of data.

The Impact of CVE-2021-34991

The impact of CVE-2021-34991 is rated high, with a CVSS base score of 8.8. Attackers can execute code with high confidentiality, integrity, and availability impacts.

Technical Details of CVE-2021-34991

CVE-2021-34991 is categorized as a stack-based buffer overflow vulnerability under CWE-121.

Vulnerability Description

The vulnerability arises from a lack of proper validation in the UPnP service of NETGEAR R6400v2 routers, leading to code execution by attackers in the root context.

Affected Systems and Versions

Affected installations of NETGEAR R6400v2 routers running version 1.0.4.106_10.0.80 are susceptible to CVE-2021-34991.

Exploitation Mechanism

The vulnerability is exploited by manipulating the uuid request header, allowing attackers to execute arbitrary code.

Mitigation and Prevention

To address CVE-2021-34991, immediate action must be taken to secure vulnerable systems and prevent unauthorized access.

Immediate Steps to Take

Admins should apply security patches provided by NETGEAR and monitor network traffic for any suspicious activities.

Long-Term Security Practices

Implement network segmentation, employ strong access controls, and regularly update firmware to enhance overall security.

Patching and Updates

Regularly check for firmware updates from NETGEAR and apply patches promptly to mitigate the risk of exploitation.