CVE-2021-30141 in Friendica
Summary
by MITRE • 04/06/2021
** DISPUTED ** Module/Settings/UserExport.php in Friendica through 2021.01 allows settings/userexport to be used by anonymous users, as demonstrated by an attempted access to an array offset on a value of type null, and excessive memory consumption. NOTE: the vendor states "the feature still requires a valid authentication cookie even if the route is accessible to non-logged users."
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Analysis
by VulDB Data Team • 06/27/2024
The vulnerability identified as CVE-2021-30141 affects the Friendica social networking platform version 2021.01 and earlier, specifically targeting the Module/Settings/UserExport.php component. This issue represents a potential security misconfiguration that could allow unauthorized access to user export functionality, though the vendor has disputed the severity by asserting that valid authentication cookies are still required for access. The vulnerability manifests when anonymous users attempt to access the settings/userexport endpoint, which should theoretically be restricted to authenticated users. However, the implementation appears to have a flaw where the route remains accessible to unauthenticated users, creating an attack surface that could be exploited by malicious actors.
The technical implementation of this vulnerability stems from improper access control validation within the Friendica application's routing system. When an anonymous user attempts to access the user export functionality, the system fails to properly validate authentication status before processing the request. This leads to an array offset access error on a null value, which indicates that the application attempts to access array elements without first verifying that the required data structures exist. Such errors typically occur when code assumes certain variables will contain specific data types, but receives null values instead. The excessive memory consumption aspect suggests that the processing of these unauthorized requests consumes disproportionate system resources, potentially leading to denial of service conditions.
From an operational impact perspective, this vulnerability creates several security concerns that align with CWE-284 (Improper Access Control) and could potentially be leveraged in conjunction with other attack vectors. The ability for anonymous users to access user export functionality, even if the vendor claims authentication cookies are required, represents a significant security gap that could enable information disclosure attacks. Attackers could potentially harvest user data, including personal information, contact details, and other sensitive metadata that users might have chosen to keep private. The memory consumption aspect also poses operational risks, as excessive resource utilization could impact system performance and availability, particularly in environments with limited computational resources.
The attack surface for this vulnerability extends beyond simple information disclosure to include potential resource exhaustion attacks that align with ATT&CK technique T1499.004 (Endpoint Denial of Service). While the vendor's statement that authentication cookies are required may be accurate in some interpretations, the fact that the route remains accessible to non-logged users suggests a fundamental flaw in the application's security model. This misconfiguration could be exploited by attackers to perform reconnaissance activities, gather user information, or potentially escalate privileges if other vulnerabilities exist within the system. The vulnerability demonstrates poor input validation and access control implementation that could be leveraged in broader attack campaigns targeting social networking platforms.
Mitigation strategies should focus on strengthening access control mechanisms within the Friendica application, particularly around the user export functionality. Administrators should ensure that proper authentication checks are implemented and enforced before any user export operations are permitted. The system should be configured to reject requests from unauthenticated users attempting to access sensitive endpoints, with appropriate error handling that prevents array offset access on null values. Additionally, implementing rate limiting and resource consumption monitoring can help detect and prevent potential denial of service attacks that might exploit the excessive memory consumption aspect of this vulnerability. Regular security audits and penetration testing should be conducted to identify similar access control flaws that could compromise the integrity and availability of the platform.