CVE-2018-8949 in MISP
Summary
by MITRE
An issue was discovered in app/Model/Attribute.php in MISP before 2.4.89. There is a critical API integrity bug, potentially allowing users to delete attributes of other events. A crafted edit for an event (without attribute UUIDs but attribute IDs set) could overwrite an existing attribute.
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Analysis
by VulDB Data Team • 02/22/2023
The vulnerability identified as CVE-2018-8949 represents a critical API integrity flaw within the MISP (Malware Information Sharing Platform) software ecosystem. This issue specifically affects versions prior to 2.4.89 and resides within the app/Model/Attribute.php file, which governs how attribute data is handled and managed within the platform. The vulnerability stems from inadequate input validation and authorization checks during attribute modification operations, creating a dangerous condition where malicious actors can manipulate event data in unintended ways. The flaw manifests when a user crafts a specific API request that modifies an event while providing attribute IDs without corresponding UUIDs, enabling unauthorized access to attribute data that belongs to different events within the same platform instance.
The technical implementation of this vulnerability exploits a fundamental weakness in the attribute handling mechanism where the system fails to properly verify ownership or authorization when processing attribute modifications. When a request contains attribute IDs but lacks UUIDs, the system incorrectly assumes that the modifying user has legitimate access to all referenced attributes regardless of their actual ownership. This misconfiguration allows attackers to target attributes belonging to other users' events by simply knowing the attribute IDs, effectively bypassing the intended access controls that should prevent such cross-event data manipulation. The vulnerability operates at the application layer and leverages the API interface to execute unauthorized attribute modifications, making it particularly dangerous in multi-tenant environments where data isolation is critical.
The operational impact of this vulnerability extends far beyond simple data manipulation, as it fundamentally undermines the integrity and confidentiality of shared threat intelligence data within MISP platforms. Attackers could potentially delete, modify, or corrupt attributes that belong to other users' events, leading to data loss, false information dissemination, and compromised threat intelligence sharing. This capability particularly threatens the trust model of MISP environments where organizations rely on accurate and complete threat data from multiple sources. The vulnerability is especially concerning in collaborative threat intelligence sharing scenarios where different organizations contribute and consume data within the same platform, as it could enable malicious actors to disrupt the integrity of shared threat feeds and compromise the reliability of the entire ecosystem.
Mitigation strategies for CVE-2018-8949 require immediate deployment of the patched MISP version 2.4.89 or later, which implements proper authorization checks and input validation for attribute modifications. Organizations should also implement additional security controls such as API rate limiting, enhanced logging of attribute modification operations, and regular audit procedures to detect unauthorized access attempts. The vulnerability aligns with CWE-284 (Improper Access Control) and represents a clear violation of the principle of least privilege in information security. From an ATT&CK framework perspective, this vulnerability maps to techniques involving privilege escalation and credential access, specifically targeting the T1078 Valid Accounts and T1484 Defense Evasion sub-techniques. Organizations should also consider implementing network segmentation controls and monitoring for anomalous API access patterns that might indicate exploitation attempts, while ensuring that all API endpoints properly validate both attribute ownership and modification authorization before processing any requests.