CVE-2023-36633 in FortiMail
Summary
by MITRE • 11/14/2023
An improper authorization vulnerability [CWE-285] in FortiMail webmail version 7.2.0 through 7.2.2 and before 7.0.5 allows an authenticated attacker to see and modify the title of address book folders of other users via crafted HTTP or HTTPs requests.
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Analysis
by VulDB Data Team • 12/08/2023
This vulnerability represents a critical authorization flaw that undermines the fundamental security principles of user isolation and data protection within FortiMail's webmail interface. The issue manifests as an improper authorization condition where authenticated users can bypass normal access controls to manipulate address book folder metadata belonging to other users. This vulnerability falls under CWE-285, which specifically addresses insufficient authorization mechanisms that allow unauthorized access to resources or data. The flaw exists in versions 7.2.0 through 7.2.2 and affects systems prior to the 7.0.5 release, indicating a regression or oversight in the authorization implementation that was not properly addressed in the 7.2.x release cycle.
The technical exploitation of this vulnerability occurs through crafted HTTP or HTTPS requests that manipulate the address book folder title modification endpoints. An authenticated attacker can construct specific API calls or web requests that target the folder management functionality, allowing them to both read and modify folder titles that should only be accessible to the folder owner. This represents a direct violation of the principle of least privilege and demonstrates a failure in access control validation. The attack vector is particularly concerning because it operates at the application layer, requiring only valid authentication credentials rather than administrative privileges or more sophisticated exploitation techniques.
The operational impact of this vulnerability extends beyond simple data modification, as it creates opportunities for social engineering attacks, information disclosure, and potential escalation of privileges. An attacker could rename folders to misleading titles, potentially confusing other users or hiding malicious activities within seemingly legitimate organizational structures. The ability to view other users' folder titles also provides reconnaissance information about user identities, organizational structure, and potentially sensitive business relationships. This vulnerability aligns with ATT&CK technique T1078.004, which covers legitimate credentials and privileges gained through manipulation of application-level access controls, and T1566.002, which involves social engineering through manipulation of legitimate application features.
Organizations utilizing FortiMail versions within the affected range face significant risk of unauthorized data access and potential information leakage. The vulnerability enables attackers to gain insights into user behavior patterns, organizational hierarchies, and potentially sensitive business communications. System administrators should prioritize immediate patching to version 7.0.5 or later, which contains the necessary authorization fixes. Additional mitigations include implementing network segmentation to limit access to the webmail interface, enabling strict access controls on the web application, and conducting thorough security audits of user access permissions. The vulnerability also highlights the importance of regular security assessments and proper authorization testing during software development cycles to prevent such regressions in security controls.