CVE-2025-65113 is a vulnerability identified in the open source video sharing platform ClipBucket v5, specifically affecting versions prior to 5.5.2 - #164. The root cause is an authorization bypass in the AJAX-based content flagging system, which allows any unauthenticated user to flag any type of content on the platform, including users, videos, photos, and collections. This bypass occurs because the system does not enforce proper authorization checks before processing flagging requests. The vulnerability is categorized under CWE-770, indicating allocation of resources without limits or throttling, which means the system can be overwhelmed by excessive flagging requests. Attackers can exploit this flaw to perform mass flagging attacks that disrupt content availability and abuse the moderation system by flooding it with false flags. This can degrade the user experience, cause legitimate content to be unfairly penalized or removed, and increase the operational burden on administrators. The CVSS v3.1 base score is 6.5 (medium severity), reflecting that the attack vector is network-based, requires no privileges or user interaction, and impacts integrity and availability but not confidentiality. The vulnerability has been publicly disclosed and patched in ClipBucket v5.5.2 - #164. No known exploits have been reported in the wild as of the publication date. Organizations running vulnerable versions should prioritize upgrading to the patched release to prevent potential abuse.

For European organizations using ClipBucket v5, this vulnerability poses a risk of content disruption and moderation system abuse. Video sharing platforms are often used by media companies, educational institutions, and social communities, making availability and content integrity critical. Mass flagging attacks could lead to legitimate content being mistakenly removed or hidden, damaging reputation and user trust. The moderation teams may face increased workload due to false flags, potentially delaying responses to genuine issues. In worst cases, attackers could leverage this to silence specific users or content, impacting freedom of expression and compliance with content regulations. Although no direct confidentiality breach occurs, the integrity and availability impacts can have significant operational and reputational consequences. The ease of exploitation (no authentication or user interaction required) increases the likelihood of opportunistic attacks, especially in environments with public-facing ClipBucket instances.

European organizations should immediately upgrade all ClipBucket v5 installations to version 5.5.2 - #164 or later, where the authorization bypass has been fixed. Until upgrades are applied, implement rate limiting and throttling on the AJAX flagging endpoints to reduce the risk of mass flagging attacks. Deploy web application firewalls (WAFs) with custom rules to detect and block abnormal flagging request patterns from unauthenticated sources. Monitor flagging activity logs for spikes or unusual patterns indicating abuse. Restrict access to flagging functionality where possible, for example by requiring authentication or CAPTCHA challenges to prevent automated abuse. Educate moderation teams to recognize and respond to mass flagging incidents promptly. Regularly audit and update platform components to ensure security patches are applied timely. Consider isolating critical content moderation systems from public access to reduce attack surface.