JumpServer Flaws Allow Attackers to Bypass Authentication and Gain Full Control

JumpServer, a widely used open-source Privileged Access Management (PAM) tool developed by Fit2Cloud, has been found to have critical security vulnerabilities.

These flaws, recently highlighted by SonarSource’s vulnerability research team, allow attackers to bypass authentication and potentially gain full control over the JumpServer infrastructure.

JumpServer acts as a centralized gateway to internal networks, offering features like SSH, RDP, and FTP tunneling through a user-friendly web interface.

However, its compromised state can grant attackers access to the entire internal network.

Technical Details of the Vulnerabilities

The vulnerabilities primarily stem from architectural mistakes, particularly inadequate isolation between microservices.

JumpServer’s architecture includes several independent components, such as the Core API, Database, Koko, Celery, and Web Proxy, each running as a Docker container.

The Core API handles authentication and authorization, while Koko manages tunneling functions like SSH connections.

The vulnerabilities exploit weaknesses in public key authentication and multi-factor authentication (MFA) mechanisms.

For instance, attackers can impersonate the Koko service by directly accessing the Core API via the web interface, bypassing public key validation.

Additionally, MFA bypass vulnerabilities allow attackers to evade rate-limiting mechanisms by manipulating the remote IP address in API requests.

Impact and Fixes

These vulnerabilities, tracked under CVEs like CVE-2023-43650, CVE-2023-43652, and CVE-2023-46123, were addressed in JumpServer versions 3.10.12 and 4.0.0.

The fixes include separating public key authentication APIs, introducing state tracking for partial success in SSH authentication, and enhancing MFA by trusting only requests originating from Koko.

Organizations using JumpServer are advised to update to the latest patched versions to prevent potential attacks.

The collaboration between researchers and Fit2Cloud has been commended for promptly addressing these security issues, underscoring the importance of continuous security assessments and secure coding practices.

Investigate Real-World Malicious Links & Phishing Attacks With Threat Intelligence Lookup – Try for Free