CVE-2017-16804 in Redmine
Summary
by MITRE
In Redmine before 3.2.7 and 3.3.x before 3.3.4, the reminders function in app/models/mailer.rb does not check whether an issue is visible, which allows remote authenticated users to obtain sensitive information by reading e-mail reminder messages.
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Analysis
by VulDB Data Team • 01/10/2023
The vulnerability identified as CVE-2017-16804 affects Redmine versions prior to 3.2.7 and 3.3.x versions before 3.3.4, specifically within the reminders functionality implemented in the app/models/mailer.rb file. This flaw represents a critical information disclosure vulnerability that undermines the application's access control mechanisms. The issue stems from the absence of proper visibility checks when generating email reminder messages, creating a scenario where authenticated users can exploit this weakness to gain unauthorized access to sensitive issue data.
The technical flaw manifests in the mailer.rb model where the reminder function fails to validate whether the authenticated user has proper permissions to view specific issues before including issue details in email notifications. This oversight allows attackers to craft requests that would trigger reminder emails containing information about issues they should not be able to access based on their assigned roles or project permissions. The vulnerability operates under the principle of insufficient authorization checking, which is classified as CWE-285 in the Common Weakness Enumeration catalog. The flaw essentially bypasses the application's inherent access control policies by exposing internal data through email communication channels that are typically considered secure pathways for legitimate user notifications.
From an operational perspective, this vulnerability creates significant risk for organizations using Redmine for project management and issue tracking, particularly those handling sensitive business data, intellectual property, or confidential project information. An authenticated attacker can leverage this weakness to gather detailed information about issues, including descriptions, attachments, assignees, and potentially even confidential project timelines or resource allocations. The impact extends beyond simple information disclosure as it can facilitate further attacks by providing attackers with knowledge about project structure, team assignments, and issue priorities that could be used for social engineering or targeted attacks. This vulnerability aligns with ATT&CK technique T1005 (Data from Local System) and T1041 (Exfiltration Over C2 Channel) when exploited in conjunction with other attack vectors.
Organizations should immediately implement the available patches for Redmine versions 3.2.7 and 3.3.4 to address this vulnerability. The mitigation strategy involves ensuring that all email reminder functions properly validate user permissions against the target issues before including any sensitive data in notification messages. Security teams should also consider implementing additional monitoring for unusual email activity patterns and conduct regular access control audits to verify that users cannot access issues beyond their assigned permissions. The fix typically involves modifying the mailer.rb file to include proper visibility checks that align with the application's existing permission models and ensure that reminder emails only contain information accessible to the recipient user. This vulnerability highlights the importance of comprehensive security testing, particularly for functions that interact with external communication channels, and demonstrates how seemingly benign features can become attack vectors when proper access controls are not implemented.