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The CVE-2025-65113 vulnerability exploits an authorization bypass in ClipBucket v5’s AJAX flagging system.
The flaw resides in the endpoint handling flag requests, which fails to verify user authentication.
Unauthenticated attackers can send crafted HTTP POST requests to the flagging API without valid sessions.
The system does not check for login status or permissions before processing flag actions.
Parameters like object ID and content type are accepted without validation.
This allows flagging of any video, photo, user, or collection on the platform.
Attackers can manipulate these parameters to target arbitrary content identifiers.
The vulnerability enables mass flagging via automated tools like curl or scripts.
Lack of rate limiting permits unlimited flagging requests from a single source.
This overwhelms the moderation queue, disrupting content visibility.
Legitimate content may be hidden or removed due to false flags.
The issue stems from missing server-side access controls in AJAX functions.
Code assumes only logged-in users access the feature, but no enforcement exists.
Exploitation requires network access to the ClipBucket instance.
Requests are sent to endpoints like /ajax/flag.php with minimal data.
The vulnerability was present in all versions prior to 5.5.2 – 164.
The patch adds authentication checks and session validation.
It ensures only authorized users can perform flagging operations.
This fix prevents unauthenticated access and secures the functionality.
The CVE highlights critical access control lapses in web applications.
Platform: ClipBucket v5
Version: Before 5.5.2
Vulnerability: Authorization Bypass
Severity: Critical
Date: 11/28/2025
Prediction: Patched in 5.5.2
What Undercode Say:
Analytics:
curl -X POST “http://target/ajax/flag.php” -d “id=1&type=video”
Vulnerable code snippet:
if (isset($_POST[‘id’])) {
flag_content($_POST[‘id’]);
}
Patched code snippet:
session_start();
if (!$_SESSION[‘user’]) {
die(“Unauthorized”);
}
how Exploit:
Send unauthenticated POST requests.
Target multiple content IDs.
Automate with scripts.
Protection from this CVE:
Update to 5.5.2.
Implement authentication checks.
Use WAF rules.
Impact:
Mass flagging attacks.
Moderation system abuse.
Content disruption.
🎯Let’s Practice Exploiting & Learn Patching For Free:
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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