CVE-2021-42972 : Vulnerability Insights and Analysis

NoMachine Server is affected by a Buffer Overflow vulnerability, allowing local attackers to execute arbitrary code in kernel mode or cause denial of service via specially crafted I/O Request Packet.

Understanding CVE-2021-42972

What is CVE-2021-42972?

NoMachine Server versions above 4.0.346 and below 7.7.4 are vulnerable to Buffer Overflow, enabling attackers to execute code or crash the OS.

The Impact of CVE-2021-42972

The vulnerability allows attackers to exploit the IOCTL Handler 0x22001B, leading to arbitrary code execution in kernel mode or denial of service through memory corruption.

Technical Details of CVE-2021-42972

Vulnerability Description

Local attackers can exploit NoMachine Server's IOCTL Handler to execute code or cause OS crashes via malicious I/O Request Packet.

Affected Systems and Versions

Vulnerable versions: NoMachine Server above 4.0.346 and below 7.7.4

Exploitation Mechanism

Attackers craft I/O Request Packets to trigger buffer overflow, enabling code execution or denial of service.

Mitigation and Prevention

Immediate Steps to Take

Update NoMachine Server to a patched version.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Implement the principle of least privilege to minimize attack surface.
Regularly apply security patches and updates.

Patching and Updates

Ensure timely installation of security updates to mitigate the risk of buffer overflow and code execution.