CVE-2021-33742 is a vulnerability that was discovered in May 2021. It is an authentication bypass flaw in Pulse Connect Secure (PCS), a popular SSL VPN solution used by many organizations worldwide. The vulnerability allows unauthenticated attackers to remotely execute arbitrary code on the vulnerable system, which can result in complete compromise of the target organization's network.
The exploitation of this vulnerability has been linked to a series of cyberattacks that have affected numerous organizations around the world. These attacks were attributed to an advanced persistent threat group known as UNC2630, believed to be based in China. The group was observed exploiting the vulnerability in combination with other zero-day vulnerabilities to gain access to targeted networks and steal sensitive data.
To mitigate the risk associated with CVE-2021-33742, organizations using PCS are urged to apply the vendor-provided security patches immediately. Additionally, it is recommended to perform a thorough review of network logs and activity to detect any signs of compromise. Organizations should also consider implementing multi-factor authentication and restricting access to the VPN only to authorized users and devices.