CVE-2026-108950 in OSSN
Summary
by MITRE • 10/12/2026
Open Source Social Network (OSSN) through 10.1 contains a missing authorization vulnerability in ossn_album_page_handler that allows unauthenticated attackers to download files via album/getphoto and album/getcover. Attackers can enumerate sequential file GUIDs to retrieve friends-only album photos and other stored files without any access check.
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Analysis
by VulDB Data Team • 10/12/2026
The Open Source Social Network (OSSN) platform, specifically through version 10.1, suffers from a critical missing authorization vulnerability within its photo handling components. This flaw resides in the ossn_album_page_handler module, which is responsible for processing requests related to album management and media retrieval. The core technical deficiency lies in the absence of proper access control checks when executing endpoints such as album/getphoto and album/getcover. These endpoints are designed to serve image files associated with user albums but fail to validate whether the requesting entity possesses the necessary permissions to view the specific content being requested. Consequently, any unauthenticated attacker can interact directly with these API-like interfaces without needing valid session tokens or login credentials, effectively bypassing the application's authentication and authorization layers entirely.
The operational impact of this vulnerability is significant for user privacy and data integrity within social networking contexts. Because OSSN relies on granular permission settings to control visibility—such as restricting certain albums to friends only—the lack of server-side validation allows malicious actors to circumvent these restrictions. Attackers can exploit the predictable nature of file identifiers by enumerating sequential Global Unique Identifiers (GUIDs). By systematically iterating through these numeric IDs, an attacker can retrieve photos and other files stored in private or restricted albums that were intended to be visible only to a specific subset of users. This capability transforms what should be protected personal media into publicly accessible data, leading to severe privacy breaches for the affected user base.
From a technical classification perspective, this vulnerability aligns with CWE-284, which describes Improper Access Control, specifically highlighting the failure to enforce restrictions on actions performed by unauthenticated users. The exploitation technique of iterating through sequential identifiers to discover hidden resources is characteristic of CWE-610, or Externally Controlled Reference to a Resource in Another Sphere, although it often overlaps with CWE-285 due to the authorization bypass aspect. In terms of offensive security frameworks, this behavior maps directly to MITRE ATT&CK technique T1078, Valid Accounts, as attackers leverage valid but unauthenticated access patterns, and more specifically relates to data exfiltration methods where sensitive information is retrieved from misconfigured endpoints without proper authentication checks.
To mitigate this vulnerability, developers must implement strict server-side authorization checks within the ossn_album_page_handler module before any file retrieval logic is executed. It is essential that every request for album content verifies both the existence of a valid user session and whether that specific user has explicit permission to view the target resource based on its privacy settings. Additionally, relying solely on sequential GUIDs for resource identification introduces predictability risks; implementing random or non-sequential identifiers can reduce the efficiency of enumeration attacks even if access controls are partially bypassed. Organizations running OSSN should immediately apply available patches that address this authorization gap and audit their deployment configurations to ensure no other endpoints suffer from similar missing validation logic.