CVE-2021-26928 : Security Advisory and Response

This article provides detailed information about CVE-2021-26928, a vulnerability in BIRD through version 2.0.7 that impacts BGP peer authentication. It discusses the potential risks, affected systems, and mitigation strategies.

Understanding CVE-2021-26928

CVE-2021-26928 is a controversial vulnerability in BIRD version 2.0.7 that affects the authentication of BGP peers. The issue could lead to route redirection, exposing systems to Denial of Service (DoS) attacks and Information Disclosure.

What is CVE-2021-26928?

CVE-2021-26928 involves a lack of password authentication functionality for BGP peers in BIRD versions up to 2.0.7. This absence of authentication can make systems vulnerable to potential route redirection attacks, posing risks of DoS and Information Disclosure.

The Impact of CVE-2021-26928

The vulnerability in BIRD could allow threat actors to exploit BGP peers' lack of password authentication, potentially leading to route manipulation, DoS attacks, and unauthorized information disclosure. Products utilizing BIRD, including Tigera configurations, may be at risk.

Technical Details of CVE-2021-26928

The technical aspects of CVE-2021-26928 include:

Vulnerability Description

BIRD through 2.0.7 lacks password authentication for BGP peers, leaving systems open to route redirection for potential DoS and Information Disclosure attacks.

Affected Systems and Versions

All systems using BIRD versions up to 2.0.7 are susceptible to this vulnerability, with potential impacts on Tigera products and other vendor solutions.

Exploitation Mechanism

Threat actors can exploit the absence of BGP peer authentication in BIRD to redirect routes, launch DoS attacks, and potentially access sensitive information.

Mitigation and Prevention

To address CVE-2021-26928, consider the following:

Immediate Steps to Take

Deploy network security measures like filtering outbound and inbound BGP traffic to mitigate the risk of route hijacking. Regularly monitor BGP sessions for any unusual behavior.

Long-Term Security Practices

Enhance network security practices by implementing secure BGP configurations, enabling password authentication for BGP peers, and staying informed about relevant security updates.

Patching and Updates

Update BIRD to version 2.0.8 or newer to address the vulnerability, ensuring that password authentication for BGP peers is properly configured.