CVE-2023-3587 in Server
Summary
by MITRE • 07/17/2023
Mattermost fails to properly show information in the UI, allowing a system admin to modify a board state allowing any user with a valid sharing link to join the board with editor access, without the UI showing the updated permissions.
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Analysis
by VulDB Data Team • 07/17/2023
The vulnerability identified as CVE-2023-3587 represents a critical access control flaw within the Mattermost collaboration platform that directly impacts the integrity of board sharing permissions. This issue stems from a fundamental misalignment between the user interface representation and the actual system state, creating a scenario where administrative actions can be executed without proper visibility into the resulting security implications. The flaw specifically affects the board sharing functionality where system administrators can manipulate board states through backend operations while the graphical interface fails to accurately reflect these changes to the user.
This technical deficiency manifests as a user interface synchronization problem that violates core security principles of least privilege and transparency in access control mechanisms. The vulnerability allows for privilege escalation through a deceptive interface where administrators can grant editor access to users via sharing links without the UI updating to show the modified permissions. This creates a dangerous scenario where the system's visual representation becomes misleading, potentially enabling unauthorized access to collaborative environments. The issue is particularly concerning because it operates at the intersection of user interface design and access control enforcement, where the visual feedback loop fails to maintain consistency with the underlying system state.
The operational impact of this vulnerability extends beyond simple permission mismanagement to encompass potential data integrity breaches and unauthorized collaborative access. When system administrators modify board states through the sharing link mechanism, they inadvertently create scenarios where users can gain editor privileges without proper authorization procedures being visible or enforced. This flaw can be exploited by malicious actors who might manipulate the system to gain elevated access to collaborative spaces, potentially leading to unauthorized modifications of shared content, data leakage, or disruption of collaborative workflows. The vulnerability essentially undermines the trust model of the platform's sharing infrastructure.
From a security standards perspective, this vulnerability aligns with CWE-691, which addresses inadequate protection of automated access control mechanisms, and CWE-284, which covers improper access control. The issue also maps to ATT&CK technique T1078.004, which involves legitimate credentials used for unauthorized access, as the sharing links represent legitimate access mechanisms that can be manipulated to bypass intended access controls. The vulnerability demonstrates a classic case of incomplete mediation where the system fails to validate access permissions consistently between the interface and backend operations, creating a gap that can be exploited to achieve unauthorized access.
Mitigation strategies should focus on implementing robust synchronization mechanisms between the user interface and backend access control systems, ensuring that all permission modifications are immediately reflected in the UI and validated through proper access control checks. Organizations should enforce strict audit logging of all board sharing modifications, implement additional verification steps for permission changes, and consider implementing multi-factor authentication for sensitive board operations. The platform should also be updated to ensure proper state management where UI elements accurately represent the current access control configuration, preventing administrators from inadvertently creating security loopholes through interface misrepresentation. Regular security testing should include verification of access control consistency between interface and backend systems to prevent similar issues from persisting in future releases.