This article shows:

  • how to spin up a vulnerable MongoDB container locally;
  • why newer MongoDB versions are not exploitable by default;
  • how downgrading makes the exploit work;
  • how the attack path looks from an attacker's perspective.

Everything here is done in a controlled local lab.

Prerequisites You need:

  • Linux or macOS;
  • Docker installed;
  • Python 3;
  • basic terminal access.

No cloud. No scanning the internet.

Step 1. Why MongoBleed only works on older setups Modern MongoDB versions are secure by default.

MongoDB 6.x and later:

  • enable authentication by default;
  • restrict unauthenticated access;
  • break the MongoBleed attack path.

MongoBleed targets:

  • legacy MongoDB versions;
  • exposed port 27017;
  • authentication disabled.

That is why we intentionally downgrade.

Get the GIthub Repo from here:

git clone https://github.com/joe-desimone/mongobleed

Step 2. Start a vulnerable MongoDB container Pull and run MongoDB with no authentication.

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The docker compose.yml file has the newest mongodb image 8.2.2

So i have to downgrade the mongoDB version to validate the vulnerability and stop the container with the newest version.

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Command: sudo docker run -d -p 27017:27017 mongo:4.4 — bind_ip_all

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What this does:

  • exposes MongoDB on all interfaces;
  • disables access control;
  • mimics a common legacy misconfiguration.

Verify it is running: sudo docker ps

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You should see:

  • image: mongo:4.4
  • port: 0.0.0.0:27017

Step 3. Verify unauthenticated access Before running any exploit, confirm manual access.

Command: mongo — host 127.0.0.1 — port 27017

If you immediately get a Mongo shell, the instance is vulnerable.

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Run: show dbs use admin

No login. No password. Full access.

MongoDB will even warn you: Access control is not enabled for the database. Read and write access is unrestricted

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That warning is the vulnerability.

Step 4. Clone the MongoBleed PoC Now move to the exploit.

Clone the repository: git clone https://github.com/joe-desimone/mongobleed.git cd mongobleed

Install requirements: pip3 install -r requirements.txt

Step 5. Run MongoBleed correctly The tool expects host and port as flags.

Correct command: python3 mongobleed.py — host 127.0.0.1 — port 27017

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What the tool does:

  • checks unauthenticated access;
  • enumerates databases;
  • attempts data interaction using predictable offsets.

If the target is vulnerable, the tool confirms it.

This maps directly to CVE-2025–14847.

Step 6. Why this still matters This vulnerability exists because:

  • admins expose databases for convenience;
  • legacy containers stay online for years;
  • port exposure is forgotten after testing.

No exploit sophistication is needed. Any scanner can find this. Any script can abuse it.

Attack impact:

  • full data exfiltration;
  • data deletion;
  • ransomware staging;
  • credential harvesting from stored secrets.

Step 7. Fixing the issue Mitigation is straightforward.

Minimum requirements:

  • enable authentication;
  • bind MongoDB to localhost or private networks only;
  • firewall port 27017;
  • upgrade MongoDB.

Example secure config:

  • no public binding;
  • auth enabled;
  • network segmentation.

Re-test after fixing. The exploit should fail immediately.

Conclusion MongoBleed is a configuration failure, not a software bug.

Downgrading MongoDB in a lab makes this visible. Running it locally shows how trivial the attack path is.

Most real-world breaches don't start with advanced exploits. They start with exposed services like this.

Hands-on labs make that reality impossible to ignore.