CVE-2015-7315 in Plone
Summary
by MITRE
Plone 3.3.0 through 3.3.6, 4.0.0 through 4.0.10, 4.1.0 through 4.1.6, 4.2.0 through 4.2.7, 4.3.0 through 4.3.6, and 5.0rc1 allows remote attackers to add a new member to a Plone site with registration enabled, without acknowledgment of site administrator.
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Analysis
by VulDB Data Team • 12/30/2022
The vulnerability identified as CVE-2015-7315 affects multiple versions of the Plone content management system, specifically targeting the user registration functionality. This issue represents a significant security flaw in the authentication and authorization mechanisms that govern member creation within Plone environments. The vulnerability exists across several major release branches including versions 3.x, 4.x, and the early 5.0 release candidate, indicating a widespread problem that has persisted across multiple iterations of the platform. The flaw directly impacts sites that have enabled public user registration, which is a common configuration for community-driven websites and portals that require user participation.
The technical nature of this vulnerability stems from insufficient validation and authorization checks during the user registration process. When a site administrator enables public registration, the system should typically require administrative approval or acknowledgment before new members can be added to the system. However, this vulnerability allows remote attackers to bypass these necessary checks and automatically create new user accounts without the required administrative confirmation. The flaw essentially undermines the intended security controls that protect against unauthorized membership additions, creating a pathway for malicious actors to populate the system with unwanted accounts.
From an operational perspective, this vulnerability poses substantial risks to Plone site administrators and organizations relying on the platform for content management. The ability to add members without administrative acknowledgment creates opportunities for spam account creation, potential credential stuffing attacks, and unauthorized access to restricted content. Attackers could exploit this weakness to flood the system with dummy accounts, potentially leading to resource exhaustion or creating a vector for further attacks. The vulnerability particularly affects sites that depend on controlled membership for access to sensitive content or collaborative features, as unauthorized users could gain unintended access to restricted areas.
The impact of this vulnerability aligns with CWE-639, which addresses authorization flaws in web applications, and can be mapped to ATT&CK technique T1078 for legitimate credentials usage and T1496 for resource hijacking. Organizations using affected Plone versions face potential reputational damage and compliance issues, especially in regulated environments where user access control is critical. The vulnerability demonstrates a failure in the principle of least privilege, where unauthorized entities can perform actions that should be restricted to privileged administrators. Security teams must understand that this weakness creates a persistent backdoor for unauthorized membership creation that could remain undetected for extended periods.
Mitigation strategies for CVE-2015-7315 require immediate action from affected organizations, including upgrading to patched versions of Plone where available. The recommended approach involves implementing proper access controls and authorization checks during the registration process, ensuring that all membership additions require explicit administrative approval. Organizations should also consider implementing additional security measures such as CAPTCHA verification, email confirmation requirements, and rate limiting for registration attempts. Network-level controls and monitoring should be enhanced to detect unusual patterns of account creation, while regular security audits should verify that registration policies are properly enforced. The vulnerability underscores the critical importance of maintaining up-to-date software versions and implementing comprehensive security controls around user management functions.