CVE-2021-43958 in FishEye
Summary
by MITRE • 03/16/2022
Various rest resources in Fisheye and Crucible before version 4.8.9 allowed remote attackers to brute force user login credentials as rest resources did not check if users were beyond their max failed login limits and therefore required solving a CAPTCHA in addition to providing user credentials for authentication via a improper restriction of excess authentication attempts vulnerability.
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Analysis
by VulDB Data Team • 10/07/2024
The vulnerability identified as CVE-2021-43958 affects Atlassian Fisheye and Crucible applications prior to version 4.8.9, representing a critical weakness in the authentication system that directly impacts user account security. This issue stems from an improper restriction of excess authentication attempts, which is classified under CWE-307 and aligns with ATT&CK technique T1110.003 for Brute Force. The flaw allows remote attackers to exploit the system's failure to enforce proper account lockout mechanisms, enabling them to systematically guess user credentials through automated attacks without encountering the expected CAPTCHA verification barriers that should normally be triggered after multiple failed login attempts.
The technical implementation of this vulnerability occurs within the REST API endpoints of the Fisheye and Crucible platforms where authentication requests are processed. These specific resources fail to properly validate whether a user account has exceeded its maximum allowed failed login attempts before accepting authentication credentials. This oversight means that attackers can continuously submit authentication requests without the system enforcing the standard security measure of requiring CAPTCHA verification after a predetermined number of failed attempts. The vulnerability essentially bypasses the intended rate limiting and account protection mechanisms that should prevent automated credential guessing attacks.
From an operational perspective, this vulnerability creates significant risk for organizations using affected versions of Fisheye and Crucible, as it enables attackers to perform dictionary attacks, credential stuffing, and brute force operations against user accounts without the usual security protections. The impact extends beyond simple unauthorized access, as successful exploitation could lead to complete system compromise, data exfiltration, and potential lateral movement within the network. Organizations with sensitive code repositories and collaboration environments are particularly vulnerable since these platforms often contain proprietary source code and development artifacts that represent valuable targets for cyber adversaries.
The mitigation strategy for CVE-2021-43958 requires immediate deployment of Atlassian's patched versions 4.8.9 and later, which properly implement authentication attempt restrictions and CAPTCHA enforcement mechanisms. System administrators should also consider implementing additional security controls such as network-level access restrictions, IP address monitoring, and enhanced logging of authentication events to detect suspicious activity patterns. Organizations should review their current authentication policies and ensure that account lockout mechanisms are properly configured and enforced across all application components, aligning with security best practices outlined in NIST SP 800-63B for authentication and account management. The vulnerability demonstrates the critical importance of proper authentication flow implementation and serves as a reminder of the necessity for comprehensive security testing of API endpoints that handle sensitive user data and authentication requests.