CVE-2020-8891 in MISP
Summary
by MITRE
An issue was discovered in MISP before 2.4.121. It did not canonicalize usernames when trying to block a brute-force series of invalid requests.
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Analysis
by VulDB Data Team • 03/30/2024
The vulnerability identified as CVE-2020-8891 affects MISP versions prior to 2.4.121 and represents a significant security flaw in the platform's authentication handling mechanisms. This issue specifically relates to the platform's inability to properly canonicalize usernames during brute-force protection attempts, creating a potential avenue for attackers to circumvent security measures designed to prevent automated login attacks.
The technical flaw stems from the absence of proper username canonicalization within the brute-force protection logic of the MISP platform. When users attempt to authenticate with invalid credentials, the system should normalize and standardize username inputs to ensure consistent blocking behavior. However, in vulnerable versions, different variations of the same username could bypass the protection mechanisms, allowing attackers to continue attempting unauthorized access without triggering the intended rate-limiting or account lockout measures.
This vulnerability directly impacts the operational security posture of MISP deployments by weakening the platform's resistance to automated credential stuffing and brute-force attacks. Attackers can exploit this weakness by submitting usernames in various formats such as uppercase, lowercase, with special characters, or using different encoding methods, thereby evading the system's built-in protection mechanisms that are designed to detect and block repetitive failed authentication attempts.
The operational impact extends beyond simple authentication bypass, as this weakness can lead to increased system load from sustained brute-force attempts, potential account compromise, and reduced overall platform reliability. Organizations relying on MISP for threat intelligence sharing and management face heightened risk of unauthorized access to sensitive security data, potentially compromising their threat detection capabilities and incident response processes.
Security practitioners should implement immediate mitigations including upgrading to MISP version 2.4.121 or later, which addresses this canonicalization issue. Additional protective measures include implementing robust rate-limiting at network level, deploying intrusion detection systems to monitor for suspicious authentication patterns, and configuring proper logging and alerting for failed authentication attempts. The vulnerability aligns with CWE-312 (Sensitive Data Exposure) and CWE-310 (Cryptographic Issues) categories, and represents a technique commonly associated with attack patterns documented in the MITRE ATT&CK framework under credential access and privilege escalation domains.
Organizations should also consider implementing multi-factor authentication as an additional layer of protection, as this vulnerability primarily affects single-factor authentication systems. The fix implemented in MISP 2.4.121 demonstrates the importance of proper input validation and canonicalization in security-critical applications, particularly those handling authentication and access control functions. Regular security assessments and penetration testing should be conducted to identify similar canonicalization issues in other components of the security infrastructure.