CVE-2024-23493 in Mattermost
Summary
by MITRE • 02/29/2024
Mattermost fails to properly authorize the requests fetching team associated AD/LDAP groups, allowing a user to fetch details of AD/LDAP groups of a team that they are not a member of.
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Analysis
by VulDB Data Team • 01/10/2025
The vulnerability identified as CVE-2024-23493 represents a critical authorization flaw within the Mattermost collaboration platform that directly impacts the security of directory integration features. This issue specifically affects the authentication and authorization mechanisms that govern access to Active Directory and LDAP group information within team contexts. The flaw exists in the way Mattermost handles requests for team-associated directory groups, creating a privilege escalation path where unauthorized users can bypass normal access controls to retrieve sensitive group membership data. Such a vulnerability undermines the fundamental security model of enterprise collaboration platforms that rely on directory services for user management and access control. The impact extends beyond simple information disclosure as it allows attackers to map out team structures, identify user roles, and potentially discover internal organizational hierarchies that should remain confidential. This type of vulnerability is particularly concerning in enterprise environments where Mattermost serves as a primary communication platform and where directory integration is essential for user provisioning and access management.
The technical implementation of this vulnerability stems from insufficient input validation and access control enforcement within Mattermost's directory synchronization and group membership retrieval components. When users make requests to fetch AD/LDAP group details associated with specific teams, the system fails to properly verify whether the requesting user has legitimate authorization to access that particular group information. This authorization gap exists at the application layer where the platform should enforce team membership boundaries and directory group access permissions. The flaw likely manifests in the API endpoint handling group retrieval requests, where proper authentication checks are either missing or incorrectly implemented. From a cybersecurity perspective, this vulnerability aligns with CWE-285, which addresses improper authorization within software systems, and represents a classic case of insufficient access control validation. The vulnerability enables attackers to perform reconnaissance activities that would normally be restricted to authorized team members or administrators, effectively breaking the principle of least privilege that should govern access to directory group information.
The operational impact of CVE-2024-23493 extends significantly beyond the immediate technical flaw, creating substantial risks for enterprise security postures and compliance requirements. Organizations using Mattermost in regulated environments face potential violations of data protection standards such as gdpr, hipaa, and soc 2, as unauthorized access to directory group information may constitute unauthorized data access. The vulnerability allows for passive reconnaissance activities that could enable attackers to identify team structures, user roles, and organizational relationships that could be leveraged in subsequent attacks. This information disclosure could facilitate social engineering campaigns, targeted phishing attempts, or more sophisticated attacks that exploit knowledge of team compositions and user roles. From an attacker's perspective, this vulnerability provides valuable intelligence for planning targeted attacks against specific teams or user groups within the organization. The impact is particularly severe in environments where Mattermost integrates with sensitive systems or where directory group membership directly correlates with access to critical resources, potentially enabling lateral movement attacks or privilege escalation within the organization's security infrastructure.
Organizations should implement immediate mitigations to address this vulnerability through comprehensive access control reviews and system hardening measures. The primary recommendation involves strengthening the authorization checks within Mattermost's directory integration components to ensure that all requests for team-associated AD/LDAP group information properly validate user permissions and team memberships. System administrators should conduct thorough access control audits to identify and remediate similar authorization gaps throughout the platform's directory integration features. The implementation of additional logging and monitoring for directory group access requests can help detect and respond to unauthorized access attempts. Organizations should also consider implementing network-level controls to restrict access to Mattermost's directory integration endpoints and establish stricter authentication requirements for administrative functions. From a compliance standpoint, this vulnerability requires immediate attention to ensure adherence to regulatory requirements and to prevent potential security incidents that could result in significant financial and reputational damage. The remediation process should include thorough testing of access control mechanisms to ensure that the fix does not introduce new functionality issues while effectively closing the authorization gap. Additionally, organizations should review their overall directory integration security posture and consider implementing multi-factor authentication for administrative access to directory synchronization features to further reduce the attack surface.