CVE-2020-1767 in Community Edition
Summary
by MITRE
Agent A is able to save a draft (i.e. for customer reply). Then Agent B can open the draft, change the text completely and send it in the name of Agent A. For the customer it will not be visible that the message was sent by another agent. This issue affects: ((OTRS)) Community Edition 6.0.x version 6.0.24 and prior versions. OTRS 7.0.x version 7.0.13 and prior versions.
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Analysis
by VulDB Data Team • 03/20/2024
This vulnerability represents a critical authorization and integrity flaw within the OTRS Community Edition messaging platform that enables cross-agent message manipulation and impersonation. The issue stems from insufficient access controls and validation mechanisms within the draft handling functionality, allowing any authorized agent to manipulate messages created by their colleagues. The vulnerability specifically affects versions 6.0.24 and earlier of OTRS Community Edition 6.0.x, as well as versions 7.0.13 and earlier of OTRS Community Edition 7.0.x, indicating a widespread impact across multiple release lines. This represents a fundamental breakdown in the principle of least privilege and auditability that should govern multi-user ticketing systems.
The technical flaw manifests through the improper handling of draft message metadata and ownership validation during the message modification process. When Agent A creates a draft message, the system fails to properly establish or enforce ownership boundaries that would prevent Agent B from accessing, modifying, and transmitting that draft under Agent A's identity. This vulnerability is classified as a CWE-285: Improper Authorization, specifically involving insufficient access control checks during message manipulation operations. The flaw allows for message impersonation attacks where the original sender's identity is obscured from end users, creating a false sense of continuity and authenticity in communications.
The operational impact of this vulnerability extends beyond simple message manipulation to encompass serious security and compliance implications for organizations using OTRS for customer service and support operations. Customers receiving messages that appear to originate from one agent while actually being sent by another face potential risks including misinformation, unauthorized communication, and compromised trust in the support process. This vulnerability directly enables social engineering attacks where malicious agents could impersonate legitimate staff members, potentially leading to unauthorized access requests, fraudulent information disclosure, or manipulation of sensitive customer data. The attack vector aligns with ATT&CK technique T1078.004: Valid Accounts, where attackers leverage legitimate user credentials to perform unauthorized actions within the system.
Organizations should implement immediate mitigations including enhanced access control policies, mandatory audit logging of draft modifications, and validation of message ownership during transmission. The recommended approach involves strengthening the draft management system to enforce strict ownership validation before any modification operations are permitted. This includes implementing proper access control checks that verify the requesting agent's authorization to modify specific drafts and maintaining detailed audit trails of all draft manipulations. Additionally, organizations should consider implementing message integrity checks and notification mechanisms that alert senders when their drafts have been modified by other agents. The vulnerability highlights the importance of proper session management and the need for comprehensive access control validation at every interaction point within multi-user systems, particularly those handling sensitive customer communications.