CVE-2012-4390 in ownCloud
Summary
by MITRE
(1) apps/calendar/appinfo/remote.php and (2) apps/contacts/appinfo/remote.php in ownCloud before 4.0.7 allows remote authenticated users to enumerate the registered users via unspecified vectors.
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Analysis
by VulDB Data Team • 03/31/2025
The vulnerability identified as CVE-2012-4390 affects ownCloud versions prior to 4.0.7 and represents a significant information disclosure weakness that undermines the security posture of the platform. This issue specifically impacts the calendar and contacts applications within the ownCloud ecosystem, creating an attack surface that allows authenticated remote adversaries to discover and enumerate registered users within the system. The vulnerability stems from insufficient access controls and improper user enumeration mechanisms within the remote application interfaces, which were designed without adequate protection against unauthorized user discovery attempts.
The technical flaw manifests through unspecified vectors within the remote.php files located in the calendar and contacts application directories. These files handle remote communication and API interactions, but fail to implement proper authentication verification or rate limiting mechanisms that would prevent systematic user enumeration. Attackers can exploit this weakness by sending crafted requests to the affected endpoints, potentially discovering valid usernames, email addresses, or other user identifiers through indirect means. The vulnerability operates at the application layer and leverages the fact that the system provides different responses to valid versus invalid user requests, creating a timing or response pattern that reveals user existence. This type of vulnerability aligns with CWE-200, which addresses information exposure, and represents a classic case of insufficiently protected user enumeration functionality.
The operational impact of this vulnerability extends beyond simple information disclosure, as it provides attackers with valuable reconnaissance data that can be used for subsequent attacks. Once user enumeration is achieved, adversaries can conduct targeted phishing campaigns, password spraying attacks, or social engineering operations against specific individuals within the organization. The vulnerability affects the confidentiality aspect of the CIA triad by allowing unauthorized disclosure of user information that should remain private within a secure collaboration platform. Organizations using affected versions of ownCloud face increased risk of credential compromise and unauthorized access to sensitive data shared through the calendar and contacts applications, particularly in environments where user privacy is paramount.
Mitigation strategies for CVE-2012-4390 should focus on immediate patching of the affected ownCloud installations to version 4.0.7 or later, which contains the necessary fixes to prevent user enumeration. System administrators should also implement additional security controls such as rate limiting on API endpoints, enhanced logging of authentication attempts, and network-level restrictions on access to remote application interfaces. The implementation of proper access controls and input validation mechanisms should be reinforced across all application components to prevent similar vulnerabilities from emerging. Organizations should conduct regular security assessments of their ownCloud deployments to identify and remediate similar weaknesses, while also monitoring for potential exploitation attempts through network intrusion detection systems. This vulnerability serves as a reminder of the critical importance of protecting user enumeration mechanisms and maintaining up-to-date security practices in collaborative platforms, as highlighted in the ATT&CK framework's enumeration techniques that target user accounts and system information.