Full Report
A recently disclosed security vulnerability in MongoDB has come under active exploitation in the wild, with over 87,000 potentially susceptible instances identified across the world. The vulnerability in question is CVE-2025-14847 (CVSS score: 8.7), which allows an unauthenticated attacker to remotely leak sensitive data from the MongoDB server memory. It has been codenamed MongoBleed. "A flaw
Analysis Summary
# Vulnerability: MongoBleed - Unauthenticated Memory Leak in MongoDB (CVE-2025-14847)
## CVE Details
- CVE ID: CVE-2025-14847
- CVSS Score: 8.7 (High)
- CWE: Not explicitly stated, related to improper input validation/decompression handling leading to memory disclosure.
## Affected Systems
- Products: MongoDB Server
- Versions: Not explicitly listed, but patches are provided for 8.2.3, 8.0.17, 7.0.28, 6.0.27, 5.0.32, and 4.4.30. It's implied that versions prior to these patches are vulnerable.
- Configurations: Instances with zlib compression enabled (which is the default configuration). The vulnerability also affects the Ubuntu `rsync` package due to zlib usage.
## Vulnerability Description
CVE-2025-14847, codenamed MongoBleed, resides in the MongoDB Server's zlib message decompression implementation, specifically in `message_compressor_zlib.cpp`. An unauthenticated attacker can send malformed, compressed network packets. This triggers an issue where the logic returns the allocated buffer size (`output.length()`) instead of the actual decompressed data length. This allows the attacker to read adjacent uninitialized heap memory, leading to the remote leakage of sensitive server data, such as user information, passwords, and API keys.
## Exploitation
- Status: Exploited in the wild
- Complexity: Low (Unauthenticated, no user interaction required)
- Attack Vector: Network
## Impact
- Confidentiality: High (Leakage of sensitive data including credentials and keys)
- Integrity: Low (Primarily data disclosure, not confirmed modification)
- Availability: Low (DoS is not the primary focus, though extensive exploitation could degrade performance)
## Remediation
### Patches
Users must update to the following versions or newer:
- MongoDB 8.2.3
- MongoDB 8.0.17
- MongoDB 7.0.28
- MongoDB 6.0.27
- MongoDB 5.0.32
- MongoDB 4.4.30
- Patches for MongoDB Atlas are confirmed to be applied.
### Workarounds
1. **Disable Zlib Compression:** Start `mongod` or `mongos` with network configuration options (`networkMessageCompressors` or `net.compression.compressors`) that explicitly exclude zlib.
2. **Network Restrictions:** Restrict network exposure of MongoDB servers to trusted hosts only (least privilege access).
## Detection
- Indicators of Compromise: Monitoring MongoDB logs for anomalous pre-authentication connection attempts, especially those sending large volumes of initial compressed payloads.
- Detection Methods and Tools: None explicitly detailed, but monitoring network traffic for suspicious handshake data/malformed compressed packets or API key exfiltration patterns post-connection is recommended.
## References
- Vendor Advisory: Vendor advisories are implied by the patch availability and MongoDB forum post.
- Relevant Links:
- General Advisory: `https://thehackernews.com/2025/12/mongodb-vulnerability-cve-2025-14847.html`
- MongoDB Security Update: `https://www.mongodb.com/community/forums/t/important-mongodb-patch-available/332977`
- MongoBleed Tool/Info: `https://github.com/joe-desimone/mongobleed`
- Technical Analysis (OX Security): `https://www.ox.security/blog/attackers-could-exploit-zlib-to-exfiltrate-data-cve-2025-14847/#technical_analysis`
- Security Researcher Details (Wiz): `https://www.wiz.io/blog/mongobleed-cve-2025-14847-exploited-in-the-wild-mongodb`