CVE-2020-25200 Scanner

Pritunl is an open-source VPN server software used by organizations to enable secure remote access to their network. It allows users to create, manage, and connect to virtual private networks (VPNs) with ease, facilitating encrypted communications over the internet. The software is typically used by IT departments and businesses of various sizes that need to provide secure remote connectivity for their employees and contractors. Pritunl supports a variety of authentication methods and integrations, making it a versatile choice for many network configurations. It is often deployed on cloud environments as well as on-premises servers. The platform is valued for its straightforward setup and comprehensive management features for large scale user and infrastructure management.

Username enumeration is a vulnerability that allows attackers to determine valid usernames in a system based on the system's response to invalid login attempts. In Pritunl version 1.29.2145.25, the login endpoint's error responses can differ based on whether a submitted username exists in the system, inadvertently disclosing valid username information. Such a vulnerability may assist attackers in refining targeted attacks, as they can identify valid usernames and potentially proceed with more sophisticated attacks like password spraying or brute-force attacks. Mitigating username enumeration usually involves implementing consistent error messages in the authentication process, ensuring the same response regardless of the validity of the username or password entered.

The vulnerability in Pritunl is specifically related to the /auth/session endpoint, where attackers can send login requests with various usernames. Through observing error response messages, attackers can infer which usernames are valid based on the discrepancies in these responses. For instance, a status code response of 400 along with specific wording in the response body indicates that a particular username may be correct or incorrect. This endpoint thus becomes a valuable target for attackers looking to build an inventory of valid usernames for the VPN service, thereby potentially compromising the system's security posture.

If successfully exploited, this vulnerability can lead to significant impacts on the affected systems. Once valid usernames are discovered, attackers are better positioned to launch credential stuffing attacks, especially if known passwords from public breaches are used. Targeted attacks may become more feasible, compromising the confidentiality, and potentially leading to unauthorized access to sensitive information. Organizations might experience increased attacks against their user authentication mechanisms, resulting in potential downtime, loss of data integrity, and ultimately, reputation damage. Addressing such vulnerabilities is crucial to maintaining secure and robust authentication processes.

REFERENCES

• https://github.com/lukaszstu/pritunl-CVE-2020-25200/blob/master/CVE-2020-25200