CVE-2021-36798 : Security Advisory and Response

A Denial-of-Service (DoS) vulnerability was discovered in Team Server in HelpSystems Cobalt Strike 4.2 and 4.3, allowing remote attackers to crash the C2 server thread and disrupt communication with beacons.

Understanding CVE-2021-36798

This section provides insights into the impact, technical details, and mitigation strategies related to CVE-2021-36798.

What is CVE-2021-36798?

The vulnerability found in HelpSystems Cobalt Strike 4.2 and 4.3 enables attackers to execute a DoS attack on the Team Server, leading to the crashing of the C2 server thread and disrupting beacons' communication.

The Impact of CVE-2021-36798

CVE-2021-36798 poses a significant threat as it allows malicious actors to halt operations by causing a denial-of-service condition on the affected system. The inability to communicate with beacons can disrupt critical processes and compromise system stability.

Technical Details of CVE-2021-36798

Explore the specific aspects of the vulnerability, including its description, affected systems, versions, and exploitation mechanisms.

Vulnerability Description

The vulnerability resides in the Team Server component of HelpSystems Cobalt Strike 4.2 and 4.3, permitting remote attackers to exploit it for launching DoS attacks, resulting in the server thread crash and communication blockage with beacons.

Affected Systems and Versions

HelpSystems Cobalt Strike versions 4.2 and 4.3 are confirmed to be impacted by this vulnerability. Systems running these versions are at risk of potential exploitation.

Exploitation Mechanism

By leveraging CVE-2021-36798, threat actors can send specially crafted requests to the Team Server, inducing a state where the C2 server thread crashes, preventing normal communication with beacons.

Mitigation and Prevention

Learn about the immediate steps to secure your systems, implement long-term security practices, and apply necessary patches and updates.

Immediate Steps to Take

To mitigate the risks associated with CVE-2021-36798, organizations should consider restricting network access to vulnerable systems, monitoring for any suspicious activities, and implementing firewall rules to block malicious traffic.

Long-Term Security Practices

Incorporating regular security assessments, ensuring timely software updates, and educating users on safe computing practices can enhance the overall security posture of an organization and reduce the likelihood of successful cyberattacks.

Patching and Updates

It is essential to apply the latest patches released by HelpSystems for Cobalt Strike, addressing the identified vulnerability and enhancing the overall security of the software.