# the mongo db situation is crazy

Source: https://www.youtube.com/watch?v=9Wg6tiaar9M
Recap page: https://rapidrecap.app/video/9Wg6tiaar9M
Generated: 2025-12-28T15:33:57.66+00:00

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## Quick Overview

The MongoDB vulnerability, dubbed "MongoBleed" (CVE-2023-14847), allows an unauthenticated attacker to leak sensitive server memory by exploiting a flaw in the zlib decompression function when handling compressed messages with an inflated uncompressed size claim, effectively leaking server secrets like passwords and keys from adjacent memory allocations.

**Key Points:**
- The MongoDB vulnerability, CVE-2023-14847, is an Unauthenticated Memory Leak Exploit stemming from a flaw in MongoDB's zlib message decompression.
- The exploit works by sending a compressed message with an artificially inflated 'uncompressedSize' claim, causing MongoDB to allocate a large buffer and then read uninitialized memory into the response buffer.
- The demonstration shows running the proof-of-concept script against a Dockerized vulnerable MongoDB instance, resulting in memory dumps containing sensitive data like file paths.
- The vulnerability affects MongoDB versions 8.2.x (8.2.0 - 8.2.2), 8.0.x (8.0.0 - 8.0.16), 7.0.x (7.0.0 - 7.0.27), 6.0.x (6.0.0 - 6.0.26), and 5.0.x (5.0.0 - 5.0.31).
- The speaker contrasts this with the Heartbleed bug, noting that MongoBleed allows reading memory without authentication, unlike Heartbleed which required a valid TLS connection.
- The host notes that MongoDB Atlas instances were patched before the exploit went public, but self-hosted instances remain at risk if not updated to the fixed versions (e.g., 8.2.3 for 8.2.x).
- The video also briefly discusses a massive data breach at Ubisoft involving Rainbow Six Siege servers, which was reportedly achieved via exploiting a MongoDB instance using MongoBleed.

![Screenshot at 00:14: The host displays the GitHub README for the 'mongobleed' proof-of-concept exploit, detailing the vulnerability as a flaw in MongoDB's zlib message decompression that returns an allocated buffer size instead of the actual decompressed size, allowing attackers to read uninitialized memory.](https://ss.rapidrecap.app/screens/9Wg6tiaar9M/00-00-14.jpg)

**Context:** The video details the exploitation of a critical vulnerability (CVE-2023-14847), nicknamed "MongoBleed," found in MongoDB's handling of compressed data messages. The host explains the technical mechanism of the memory leak, which allows unauthenticated remote attackers to read sensitive information from the server's memory by abusing the zlib decompression logic. The context shifts later to discuss real-world implications, specifically mentioning how this vulnerability was allegedly used in the recent Ubisoft data breach.

## Detailed Analysis

The presenter explains the MongoBleed vulnerability (CVE-2023-14847) in MongoDB, which is an unauthenticated memory leak. The flaw lies in the zlib message decompression routine: when an attacker sends a compressed message claiming an inflated uncompressed size, MongoDB allocates a buffer based on the attacker's inflated size claim. When zlib decompresses the actual data into this buffer, it can read past the end of the actual data into uninitialized memory, returning that memory content to the attacker. The script shown, 'mongobleed.py', exploits this by sending a specially crafted message and receiving data chunks that contain memory contents, such as file paths from a Docker environment. The exploit is successful without authentication. The affected versions range from 5.0.x up to 8.2.x, with specific fixed versions listed. The host notes that MongoDB Atlas instances were patched before the public disclosure, but self-hosted instances must be manually upgraded. The vulnerability's mechanism is compared to the famous Heartbleed bug. Finally, the presenter connects this exploit to real-world incidents, noting reports that a group exploited a MongoDB instance at Ubisoft using MongoBleed to exfiltrate internal source code and that other groups exploited Rainbow Six Siege services, potentially leveraging similar vulnerabilities or the MongoBleed exploit itself.

### MongoBleed Vulnerability Explained

- A flaw in MongoDB's zlib decompression returns the allocated buffer size instead of the actual decompressed data length
- This allows attackers to read uninitialized memory
- Exploitation requires sending a compressed message with an inflated 'uncompressedSize' claim
- The bug causes MongoDB to treat the entire buffer as valid data during BSON parsing

### Affected Versions

- 8.2.x (8.2.0 - 8.2.2 fixed in 8.2.3)
- 8.0.x (8.0.0 - 8.0.16 fixed in 8.0.17)
- 7.0.x (7.0.0 - 7.0.27 fixed in 7.0.28)
- 6.0.x (6.0.0 - 6.0.26 fixed in 6.0.27)
- 5.0.x (5.0.0 - 5.0.31 fixed in 5.0.32)

### Proof-of-Concept Execution

- The host runs the 'mongobleed.py' script against a locally running vulnerable Docker container
- The script scans offsets and successfully leaks memory contents, including file paths like '/var/lib/desktop-container/daemon/lo.conf'

### Real-World Impact Discussion

- The host references external reports regarding a Ubisoft breach where attackers exploited a MongoDB instance via MongoBleed to steal internal source code
- Another group allegedly exploited a Rainbow Six Siege service, leading to the gifting of massive amounts of in-game currency to players.

![Screenshot at 00:13: The host displays the GitHub README for the 'mongobleed' proof-of-concept, showing the vulnerability steps and the table of affected MongoDB versions.](https://ss.rapidrecap.app/screens/9Wg6tiaar9M/00-00-13.jpg)
![Screenshot at 01:04: The host navigates the file structure of the mongobleed repository, highlighting the 'mongobleed.py' script that contains the exploit logic.](https://ss.rapidrecap.app/screens/9Wg6tiaar9M/00-01-04.jpg)
![Screenshot at 01:42: A close-up on the Python code within the 'send\_probe' function, showing where the payload is constructed using 'OP\_COMPRESSED' and the malicious 'buffer\_size' claim.](https://ss.rapidrecap.app/screens/9Wg6tiaar9M/00-01-42.jpg)
![Screenshot at 02:29: The host references an XKCD comic explaining the Heartbleed bug mechanism, drawing a parallel to how the size miscalculation in MongoBleed functions.](https://ss.rapidrecap.app/screens/9Wg6tiaar9M/00-02-29.jpg)
![Screenshot at 03:07: The host runs the 'docker-compose up' command, starting the vulnerable MongoDB service container, which prompts a Windows Security firewall alert.](https://ss.rapidrecap.app/screens/9Wg6tiaar9M/00-03-07.jpg)