CVE-2021-33500 : What You Need to Know

PuTTY before 0.75 on Windows allows remote servers to cause a denial of service (Windows GUI hang) by telling the PuTTY window to change its title repeatedly at high speed.

Understanding CVE-2021-33500

Denial of Service vulnerability in PuTTY software.

What is CVE-2021-33500?

PuTTY before version 0.75 on Windows can be exploited by remote servers to hang the Windows GUI by rapidly changing the title, resulting in multiple SetWindowText calls.

The Impact of CVE-2021-33500

The vulnerability has a high severity impact on the availability of Windows systems running PuTTY, potentially leading to a denial of service attack.

Technical Details of CVE-2021-33500

Details on the vulnerability in PuTTY software.

Vulnerability Description

The issue allows remote servers to cause a denial of service by manipulating the PuTTY window title at high speed, leading to excessive SetWindowText calls.

Affected Systems and Versions

All versions of PuTTY prior to 0.75 on Windows are affected by this vulnerability.

Exploitation Mechanism

Attackers can exploit this vulnerability remotely by sending the PuTTY window repeated title change requests.

Mitigation and Prevention

Measures to mitigate the impact of CVE-2021-33500.

Immediate Steps to Take

Update PuTTY to version 0.75 or later to prevent exploitation of this vulnerability.

Long-Term Security Practices

Regularly update PuTTY and other software to the latest versions to protect against potential vulnerabilities.

Patching and Updates

Stay informed about security patches and update PuTTY and other software regularly to enhance system security.