CVE-2026-77927 in ClipBucket
Summary
by MITRE • 09/18/2026
ClipBucket v5 before 5.5.3-#182 contains a blind SQL injection vulnerability that allows authenticated users to extract arbitrary data from the database by submitting the check_photo parameter as an array to bypass the clean_requests() sanitization function in ClipBucket.class.php. Attackers can pass unsanitized array elements through the bulk deletion handler in manage_photos.php to photo_exists() in photos.class.php, where non-numeric values are interpolated directly into a SQL query, enabling time-based blind SQL injection to retrieve credential hashes and other sensitive data.
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Analysis
by VulDB Data Team • 09/18/2026
The vulnerability identified in ClipBucket versions prior to 5.5.3 constitutes a critical authenticated blind SQL injection flaw that stems from improper input validation within the application's photo management subsystem. The root cause lies in the handling of the check_photo parameter, which is processed through the bulk deletion handler located in manage_photos.php. This entry point accepts user-supplied data and passes it to the photo_exists function defined in photos.class.php without adequate sanitization or type checking for array elements. Specifically, the application relies on a clean_requests() function intended to sanitize inputs, but this mechanism fails when the check_photo parameter is submitted as an array rather than a single scalar value. This structural oversight allows attackers to bypass the initial filtering layer by exploiting the iteration logic that processes each element of the array individually, thereby exposing underlying database queries to malicious input injection.
From a technical perspective, the vulnerability manifests in photos.class.php where non-numeric values derived from the unsanitized array elements are interpolated directly into SQL query strings. Because the application does not enforce strict type constraints on these parameters before their use in database operations, an authenticated attacker can inject syntactically correct SQL commands that alter the logic of the original query. The exploitation vector is characterized as a time-based blind injection, which implies that the vulnerability does not return data directly to the user interface but instead allows for inference based on response times or application behavior changes. This method enables attackers to extract arbitrary data from the backend database incrementally by crafting payloads that trigger measurable delays when specific conditions are met, effectively turning the database into a channel for exfiltrating sensitive information such as administrator credential hashes, session tokens, and other confidential records stored within the ClipBucket infrastructure.
The operational impact of this vulnerability is severe due to its authenticated nature and the sensitivity of data accessible through it. While authentication requirements limit the pool of potential attackers compared to unauthenticated vulnerabilities, any compromised user account can be leveraged to achieve full database compromise. The ability to extract credential hashes poses a significant risk for lateral movement within an organization or offline cracking attacks that could lead to privilege escalation beyond the initial application access level. Furthermore, the extraction of arbitrary data undermines the confidentiality and integrity guarantees expected from the video hosting platform, potentially leading to exposure of user privacy information, proprietary content metadata, or system configuration details. This aligns with CWE-89 Improper Neutralization of Special Elements used in an SQL Command, highlighting a fundamental failure in input validation and parameterized query usage practices during development.
Mitigation strategies must prioritize immediate patching by upgrading ClipBucket to version 5.5.3 or later where the issue has been addressed through improved sanitization logic for array inputs. In environments where updating is not immediately feasible, defensive measures should include implementing strict type casting on all database-bound parameters to ensure only expected numeric values are processed in photo-related queries. Additionally, deploying a Web Application Firewall with rules tuned to detect time-based blind SQL injection patterns can provide an additional layer of defense by identifying anomalous request behaviors associated with payload execution. Security teams should also enforce the principle of least privilege for application database accounts and enable detailed logging to monitor for unusual query latency spikes that may indicate active exploitation attempts, thereby supporting detection efforts aligned with MITRE ATT&CK techniques related to SQL injection and data exfiltration via backend services.