CVE-2021-20077 : Vulnerability Insights and Analysis

Nessus Agent versions 7.2.0 through 8.2.2 were found to inadvertently capture the IAM role security token on the local host during initial linking of the Nessus Agent when installed on an Amazon EC2 instance. This could allow a privileged attacker to obtain the token.

Understanding CVE-2021-20077

This CVE is related to Tenable Nessus Agent versions 7.2.0 through 8.2.2, impacting the security of IAM role security tokens on Amazon EC2 instances.

What is CVE-2021-20077?

This CVE refers to the vulnerability where Nessus Agent versions 7.2.0 through 8.2.2 unintentionally capture the IAM role security token on the local host during initial linking, enabling a potential attacker to acquire the token.

The Impact of CVE-2021-20077

The impact of this vulnerability is significant as it allows a privileged attacker to exploit the captured IAM role security token, potentially leading to unauthorized access and privilege escalation.

Technical Details of CVE-2021-20077

This section provides more insight into the vulnerability and its technical aspects.

Vulnerability Description

The vulnerability in Tenable Nessus Agent versions 7.2.0 through 8.2.2 involves the inadvertent capture of IAM role security tokens during the initial linking process, posing a risk of unauthorized token access.

Affected Systems and Versions

Systems running Tenable Nessus Agent versions 7.2.0 through 8.2.2 are susceptible to this security flaw, particularly when deployed on Amazon EC2 instances.

Exploitation Mechanism

The vulnerability can be exploited by a privileged attacker who gains access to the captured IAM role security token, potentially resulting in privilege escalation and unauthorized system access.

Mitigation and Prevention

To address CVE-2021-20077 and enhance system security, certain mitigation measures and preventive actions are recommended.

Immediate Steps to Take

Users should promptly update their Tenable Nessus Agent to versions beyond 8.2.2 to mitigate the vulnerability. Additionally, rotating IAM role security tokens is advisable.

Long-Term Security Practices

In the long term, organizations should implement robust security practices that involve regular security assessments, access control mechanisms, and monitoring of IAM role token usage.

Patching and Updates

Regularly monitoring security advisories from Tenable and promptly applying patches and updates is crucial to safeguard systems against known vulnerabilities.