CVE-2017-15211 in Kanboard
Summary
by MITRE
In Kanboard before 1.0.47, by altering form data, an authenticated user can add an external link to a private project of another user.
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Analysis
by VulDB Data Team • 01/03/2023
The vulnerability identified as CVE-2017-15211 affects Kanboard versions prior to 1.0.47 and represents a critical access control flaw that undermines the security model of the application. This issue allows authenticated users to manipulate form data in a way that enables them to add external links to private projects belonging to other users, effectively bypassing the intended project visibility controls. The vulnerability stems from insufficient input validation and authorization checks within the application's form processing mechanisms, creating a path for privilege escalation through data manipulation.
The technical implementation of this vulnerability exploits the lack of proper access validation during external link creation operations. When an authenticated user attempts to add an external link to a project, the application fails to verify whether the user has legitimate access rights to the target project. This weakness occurs because the form data submitted by the user can be modified to reference a different project identifier, and the system does not perform adequate authorization checks before processing the request. The flaw specifically manifests when the application relies on client-side data integrity rather than server-side validation of user permissions, creating a scenario where malicious actors can leverage their authenticated session to perform unauthorized actions.
The operational impact of this vulnerability extends beyond simple data exposure, as it enables unauthorized users to inject external links into private projects that they should not have access to. This capability can be exploited for various malicious purposes including phishing attacks, social engineering campaigns, or information gathering activities that could compromise the confidentiality and integrity of private project data. The vulnerability affects the fundamental security principle of least privilege, as it allows users to perform actions that should be restricted to project owners or administrators. Additionally, this flaw can potentially facilitate further attacks by providing attackers with access to project-specific contexts that may reveal sensitive information about project structures, timelines, or team compositions.
From a cybersecurity perspective, this vulnerability aligns with CWE-284, which addresses improper access control issues in software systems. The flaw represents a classic example of insufficient authorization checks, where the system fails to properly validate that the authenticated user has the necessary permissions to perform the requested operation. The vulnerability also relates to ATT&CK technique T1078 which covers valid accounts and legitimate credentials as a means to gain access to systems. Organizations using affected versions of Kanboard should immediately implement the available patch to address this security gap. The recommended mitigation includes upgrading to version 1.0.47 or later, which incorporates proper authorization checks and input validation mechanisms. Additionally, administrators should review access controls and monitor for unauthorized external link additions to detect potential exploitation attempts. The vulnerability demonstrates the critical importance of server-side validation in preventing authenticated privilege escalation attacks and underscores the necessity of implementing robust access control mechanisms in collaborative software platforms.