CVE-2012-6563 in Elgg
Summary
by MITRE
engine/lib/access.php in Elgg before 1.8.5 does not properly clear cached access lists during plugin boot, which allows remote attackers to read private entities via unspecified vectors.
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Analysis
by VulDB Data Team • 02/27/2019
The vulnerability identified as CVE-2012-6563 resides within the access control mechanisms of Elgg version 1.8.4 and earlier, specifically in the engine/lib/access.php file. This flaw represents a critical security oversight that undermines the fundamental access control policies designed to protect private content within the platform. The issue manifests during the plugin boot process where cached access lists fail to be properly cleared, creating a persistent security gap that can be exploited by remote attackers to gain unauthorized access to private entities.
The technical root cause of this vulnerability stems from improper memory management within the access control subsystem. During plugin initialization, the system maintains cached access control lists that should be refreshed or cleared when plugins are loaded or reloaded. However, the implementation in affected versions fails to properly invalidate these caches, leading to stale access control information remaining in memory. This cached data contains permissions and access rules that should be updated based on current plugin configurations and user contexts. When attackers exploit this weakness, they can leverage the outdated cached access lists to bypass normal access controls and retrieve private content that should be restricted to specific users or groups.
The operational impact of this vulnerability extends beyond simple information disclosure, as it fundamentally compromises the confidentiality and integrity of user data within the Elgg platform. Attackers can potentially access private messages, user profiles, content items, and other sensitive data that should be protected by access control rules. This vulnerability affects the core security model of the platform, as it undermines the trust model that users place in the system's ability to protect their private information. The unspecified vectors mentioned in the description suggest that the attack surface may be broader than initially apparent, potentially affecting various types of private entities within the platform's ecosystem.
This vulnerability aligns with CWE-200, which addresses improper exposure of sensitive information, and can be categorized under ATT&CK technique T1068, which involves exploiting vulnerabilities to gain access to systems. The flaw demonstrates poor software engineering practices in memory management and access control implementation, particularly during application lifecycle events such as plugin boot processes. Organizations using affected versions of Elgg face significant risk of data breaches, compliance violations, and reputational damage if this vulnerability remains unpatched. The vulnerability's persistence across plugin reloads means that even temporary access to the system could be leveraged to maintain unauthorized access to private content over extended periods.
The recommended mitigation strategy involves upgrading to Elgg version 1.8.5 or later, which contains the necessary patches to properly clear cached access lists during plugin boot processes. Administrators should also implement additional monitoring and logging of access control events to detect potential exploitation attempts. Security teams should conduct thorough audits of their Elgg installations to ensure that all affected versions have been updated and that proper access control policies are in place. Organizations should also consider implementing network-level monitoring to detect unusual access patterns that might indicate exploitation of this vulnerability, as the attack may not be immediately apparent through standard security scanning tools.