CVE-2021-34718 : Security Advisory and Response

A vulnerability in the SSH Server process of Cisco IOS XR Software has been identified as CVE-2021-34718. This CVE allows an authenticated, remote attacker to overwrite and read arbitrary files on the local device. The impact of this vulnerability, affected systems, exploitation mechanism, and mitigation steps are detailed below.

Understanding CVE-2021-34718

This section provides insights into the nature of the CVE-2021-34718 vulnerability.

What is CVE-2021-34718?

The vulnerability in the SSH Server process of Cisco IOS XR Software enables an attacker to overwrite and read arbitrary files on the affected device.

The Impact of CVE-2021-34718

The severity of this vulnerability is rated as HIGH. An attacker could leverage this flaw to elevate their privileges, access unauthorized files, and perform unauthorized uploads on the target device.

Technical Details of CVE-2021-34718

This section delves into the technical aspects of CVE-2021-34718.

Vulnerability Description

Insufficient input validation within the SSH Server process leads to this vulnerability. Attackers with lower-level privileges can exploit this weakness by manipulating Secure Copy Protocol (SCP) parameters during device authentication.

Affected Systems and Versions

The vulnerability impacts Cisco IOS XR Software. Specific version information is not disclosed.

Exploitation Mechanism

Authenticated, remote attackers can exploit the vulnerability by supplying malicious arguments for a file transfer method, potentially gaining unauthorized access to the device.

Mitigation and Prevention

In response to CVE-2021-34718, immediate actions and long-term security measures are essential.

Immediate Steps to Take

Users are advised to apply security updates provided by Cisco promptly. Additionally, enforcing strong authentication protocols and monitoring SCP interactions can help mitigate risks.

Long-Term Security Practices

Implementing robust input validation mechanisms, limiting user privileges, and performing regular security audits are recommended for long-term security enhancement.

Patching and Updates

Regularly check for security advisories from Cisco and apply patches as soon as they are available to safeguard systems against potential exploitation.