CVE-2019-5935 in Garoon
Summary
by MITRE
Cybozu Garoon 4.0.0 to 4.10.1 allows remote authenticated attackers to bypass access restriction to change user information without access privileges via the Item function of User Information.
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Analysis
by VulDB Data Team • 09/23/2023
Cybozu Garoon is a collaboration platform that provides user management and information sharing capabilities within enterprise environments. The vulnerability described in CVE-2019-5935 represents a critical access control flaw that allows authenticated attackers to escalate their privileges and modify user information without proper authorization. This issue affects versions 4.0.0 through 4.10.1 of the Garoon platform, indicating a widespread vulnerability across multiple releases that could impact numerous organizations relying on this collaboration tool.
The technical flaw resides within the Item function of the User Information module where proper access control checks are inadequately implemented. When authenticated users attempt to modify user information through this specific function, the system fails to validate whether the requesting user has sufficient privileges to perform such operations. This weakness creates a privilege escalation path where attackers can manipulate user data, potentially altering access rights, personal information, or administrative permissions of other users within the system. The vulnerability specifically targets the authorization mechanisms that should prevent unauthorized modifications to user profiles and settings.
The operational impact of this vulnerability extends beyond simple data modification, as it can enable attackers to compromise the integrity of the entire user management system. An attacker who successfully exploits this flaw could potentially elevate their privileges to administrative levels, modify critical user attributes, or manipulate access controls for other users. This represents a significant security risk in enterprise environments where Garoon serves as a central collaboration platform, as it could lead to unauthorized access to sensitive information, disruption of business processes, or facilitate further attacks within the network. The vulnerability is particularly dangerous because it requires only authentication to exploit, meaning that any authenticated user with basic access rights could potentially leverage this flaw.
Organizations should implement immediate mitigations including applying the vendor-provided patches and updates for affected versions of Cybozu Garoon, reviewing and strengthening access control policies, and conducting thorough security assessments of the platform. Network segmentation and monitoring of user activity within the Garoon system can help detect potential exploitation attempts. This vulnerability aligns with CWE-284, which addresses improper access control, and maps to ATT&CK technique T1078 for valid accounts and privilege escalation. Security teams should also consider implementing additional authentication controls and regularly reviewing user access rights to prevent unauthorized modifications to user information. The incident underscores the importance of proper input validation and access control implementation in enterprise collaboration platforms.