CVE-2015-8007 in MediaWiki
Summary
by MITRE
The Echo extension for MediWiki does not properly implement the hideuser functionality, which allows remote authenticated users to see hidden usernames in "non-revision based" notifications, as demonstrated by viewing a hidden username in a Thanks notification.
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Analysis
by VulDB Data Team • 06/25/2022
The CVE-2015-8007 vulnerability resides within the Echo extension of MediaWiki, a widely deployed wiki software platform that powers numerous websites including Wikipedia. This security flaw specifically targets the hideuser functionality that was designed to protect user privacy by concealing usernames from public view when users choose to hide their identities. The vulnerability represents a critical breakdown in the extension's implementation where the system fails to consistently enforce user privacy settings across all notification types, creating a significant information disclosure risk.
The technical flaw manifests in the Echo extension's handling of notifications that are not based on revision changes, such as Thanks notifications, which are used to acknowledge contributions and interactions within the wiki environment. While the extension correctly implements user hiding for revision-based notifications where changes are tracked and logged, it fails to properly apply the same privacy controls to other notification types. This inconsistency allows authenticated attackers who are logged into the system to exploit the gap in implementation and extract hidden usernames from non-revision based notifications, effectively bypassing the intended privacy controls.
The operational impact of this vulnerability extends beyond simple privacy concerns to encompass potential security risks for users who rely on anonymous participation within wiki communities. Attackers can leverage this flaw to discover the true identities of users who have chosen to hide their usernames, potentially exposing individuals to harassment, targeted attacks, or unwanted attention. The vulnerability particularly affects collaborative environments where users may hide their identities for legitimate reasons such as protecting personal information, avoiding workplace conflicts, or maintaining anonymity during sensitive discussions. This disclosure of hidden identities undermines the trust and security model that MediaWiki aims to maintain for its users.
The vulnerability aligns with CWE-610, which addresses "Remote Resources Reference in a Context That Should be Restricted," as it demonstrates how authenticated users can access resources they should not be able to view due to insufficient access controls. From an ATT&CK perspective, this issue maps to T1069.001 - "Credentials in Files" and T1566.001 - "Phishing" as it enables attackers to gather user information that could be used for social engineering attacks or credential harvesting. The flaw also relates to T1212 - "Exploitation for Credential Access" since the disclosure of hidden usernames can lead to more sophisticated attacks against users who may be targeted based on their revealed identities.
Mitigation strategies for this vulnerability involve updating the Echo extension to properly implement consistent user hiding across all notification types, ensuring that the hideuser functionality applies uniformly to both revision-based and non-revision based notifications. System administrators should immediately apply the relevant security patches provided by the MediaWiki development team, which typically involve modifying the notification handling code to enforce proper access controls regardless of notification type. Additionally, organizations should conduct thorough security reviews of their MediaWiki installations to identify similar inconsistencies in other extensions and implement comprehensive testing of privacy controls across all user-facing features. Regular monitoring and auditing of notification systems can help prevent similar vulnerabilities from emerging in other parts of the MediaWiki ecosystem.