*Published: June 2024*


Cisco has just disclosed a worrying vulnerability, tracked as CVE-2025-20156, that puts the power of IT infrastructure in the hands of low-privileged attackers. This long read will break down what went wrong in the Cisco Meeting Management REST API, how this bug can be exploited, and what you need to watch out for.

Let’s dig in—with simple explanations, live code examples, and all official sources.

What Is Cisco Meeting Management?

Cisco Meeting Management is a platform that helps admins control, schedule, and monitor video conferencing gear. Companies use it to manage meetings, users, and endpoints across their whole business.

It has a REST API that lets other software (or admins) perform management tasks without using the web interface. But this API turned out to be a big weak spot.

What Is CVE-2025-20156?

CVE-2025-20156 is a vulnerability that allows a user with any valid (low-privilege) account on the Cisco Meeting Management REST API to act as an administrator. This means they can take over all edge nodes—managing, deleting, or reconfiguring even critical infrastructure.

Why does this happen?
Because the software does not properly check if a user is authorized when handling REST API requests. Anyone signed in can send admin-level commands to the right API endpoint.

References

- Cisco Official Advisory: Cisco Security Advisory — CVE-2025-20156
- National Vulnerability Database: NVD — CVE-2025-20156

The Technical Root

Software should make sure—every time—a user does something important, that they are actually allowed to do it. The problem here: the Cisco Meeting Management REST API trusts any logged-in user for high-privilege tasks. There’s a lack of fine-grained access checks (“authorization controls”).

In programming, it looks like

# Pseudocode of the bug
def api_endpoint(request):
    # This checks if user is logged in (authenticated)
    if request.user.is_authenticated:
        # But should ALSO check: is user an admin?
        perform_admin_action()
    # ...but it doesn't

A correct version would include

def api_endpoint(request):
    if request.user.is_authenticated and request.user.role == 'admin':
        perform_admin_action()
    else:
        return "Unauthorized"

Exploiting CVE-2025-20156: Proof of Concept

*Disclaimer: This is for educational purposes only.*

Let’s say an attacker has a low-privileged account on the Cisco Meeting Management platform. To exploit the bug, they’ll craft a REST API request to a sensitive endpoint (like adding an admin, rebooting hardware, or deleting nodes).

Example using curl

curl -k -X POST \
  https://meeting-management.example.com/api/edge/admins \
  -H "Authorization: Bearer LOWUSER_TOKEN" \
  -d '{"username": "evilhacker", "password": "supersecret"}'

If you run that with a user account access token (instead of an admin one), it should be rejected. But with this CVE, it succeeds.

Why?
Because the backend only checks you’re logged in—not if your user role allows the action.

Possible Attack Flow

1. Attacker signs up / uses a regular (low privilege) account.

Uses that token to send privileged API requests that would normally require admin rights.

4. Gains administrator-level control over Cisco Meeting Management systems—maybe even entire video infrastructure.

Update immediately to a version patched against CVE-2025-20156. Cisco has released a fix:

Cisco Software Download Center

Final Thoughts

CVE-2025-20156 is a textbook case of “authentication ≠ authorization.” Developers and IT admins need to make sure every powerful API call checks not just “who are you?” but “are you allowed to do this?”

Patch now, monitor your logs, and remind your teams: least privilege is not just a nice idea—it’s necessary.


*For more technical details, visit the official Cisco advisory.*

Timeline

Published on: 01/22/2025 17:15:12 UTC
Last modified on: 01/29/2025 16:15:43 UTC