CVE-2017-9505 in Confluence
Summary
by MITRE
Atlassian Confluence starting with 4.3.0 before 6.2.1 did not check if a user had permission to view a page when creating a workbox notification about new comments. An attacker who can login to Confluence could receive workbox notifications, which contain the content of comments, for comments added to a page after they started watching it even if they do not have permission to view the page itself.
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Analysis
by VulDB Data Team • 12/28/2020
The vulnerability identified as CVE-2017-9505 affects Atlassian Confluence versions 4.3.0 through 6.2.0, representing a significant information disclosure flaw that undermines the application's access control mechanisms. This issue stems from a fundamental failure in the permission checking logic within Confluence's workbox notification system, where the application fails to validate user authorization before delivering sensitive comment content to unauthorized individuals. The flaw exists specifically during the creation of workbox notifications for new comments, creating a scenario where users can receive detailed information about content they should not be able to access.
The technical nature of this vulnerability aligns with CWE-284, which addresses improper access control issues, and represents a clear violation of the principle of least privilege in information security. When users begin watching pages in Confluence, the system should verify that they possess the appropriate permissions to view the content before generating notifications. However, the flaw allows attackers to bypass this critical check, enabling them to receive workbox notifications containing the full text of comments added to pages they cannot access. This creates a scenario where sensitive information can be disclosed to unauthorized parties through the notification system rather than through direct access attempts.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can enable attackers to gather intelligence about content, discussions, and potentially sensitive business information that they would not normally be able to access. The workbox notifications contain the actual content of comments, which could include confidential business discussions, strategic information, or other sensitive data that should remain restricted to authorized users only. This vulnerability effectively creates a covert channel for information exfiltration, allowing attackers to monitor and collect data about pages they should not be able to view, potentially leading to further exploitation opportunities or competitive intelligence gathering.
Organizations running affected Confluence versions face significant security risks from this vulnerability, as it can be exploited by any authenticated user to gain unauthorized access to restricted content through the notification system. The attack vector is particularly concerning because it does not require elevated privileges or complex exploitation techniques, merely legitimate user access to the system. The vulnerability can be exploited to monitor sensitive discussions, gather information about ongoing projects, or identify content that should remain confidential, making it a serious concern for organizations handling sensitive business information, intellectual property, or regulated data.
The recommended mitigation for CVE-2017-9505 involves upgrading to Atlassian Confluence version 6.2.1 or later, where the permission checking logic has been properly implemented to prevent unauthorized access to comment content through workbox notifications. Organizations should also implement additional monitoring of user activities and notification patterns to detect potential exploitation attempts. Security teams should review and validate access controls within their Confluence instances, ensuring that all permission checks are properly enforced throughout the application. Additionally, administrators should consider implementing network-level controls and access restrictions to limit exposure, while also reviewing user access rights to minimize the potential impact of compromised accounts. The vulnerability demonstrates the critical importance of proper access control implementation in web applications and serves as a reminder of the need for comprehensive security testing and validation of authorization mechanisms.