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MongoBleed: MongoDB Memory Disclosure (CVE-2025-14847)

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CVE-2025-14847
Memory Disclosure / Use of Uninitialized Memory
Network Pre-auth Disclosure

Overview

MongoBleed is a critical vulnerability in MongoDB that allows unauthenticated attackers to leak sensitive server memory. By sending specially crafted zlib-compressed network messages, attackers can extract fragments of memory containing credentials, secrets, or internal data — all before authentication occurs.

Technical Specifications

Attribute Details
Vulnerability ID CVE-2025-14847
Root Cause Improper handling of zlib-compressed network messages; use of uninitialized memory
Issue Type Use of uninitialized memory (memory disclosure)
Attack Vector Network (TCP, typically port 27017)
Authentication None (pre-auth)
User Interaction Not required
Affected Versions Multiple major releases prior to patched updates

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Affected Products

  • MongoDB server instances exposed to the network (default port 27017)

Attack Scenario

  1. Attacker scans the internet for exposed MongoDB servers.
  2. Attacker sends a crafted zlib-compressed packet to the MongoDB service.
  3. MongoDB processes decompression before authentication and returns data containing leaked heap memory.
  4. Attacker repeats requests, collecting additional memory fragments.
  5. Leaked fragments are reconstructed to reveal credentials, API keys, tokens, or other sensitive data.

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Potential Access Points

  • Publicly reachable MongoDB instances
  • Misconfigured hosts with open port 27017
  • Services reachable via improperly configured network rules or VPNs

Impact Assessment

  • Potential tampering with in-transit or cached database responses
  • Risk of altered configurations if credentials are obtained
  • Exposure of database credentials, API keys, and authentication tokens
  • Leakage of internal data and sensitive application secrets
  • Indirect service disruption from subsequent exploitation (credential misuse, ransomware)
  • Operational impact due to incident response and containment

Mitigation Strategies

🔄 Immediate Actions

  • Patch immediately to fixed versions: 8.2.3+, 8.0.17+, 7.0.28+, 6.0.27+, 5.0.32+, 4.4.30+
  • Restrict network access to MongoDB instances; do not expose to public internet.

🛡️ Short-term Measures

  • Disable zlib compression (networkMessageCompressors) as a temporary workaround.
  • Harden firewall rules, allowlist management IPs, and require VPN access.

🔍 Monitoring & Detection

  • Monitor logs for malformed or repeated compressed requests and unusual connection patterns.
  • Enable file integrity and credential monitoring for services that use MongoDB secrets.

🔒 Long-term Solutions

  • Adopt network segmentation and zero-trust access controls for database tiers.
  • Implement secrets rotation and minimize long-lived credentials.
  • Maintain a vulnerability management program and apply vendor patches promptly.

Resources and References

Threat Intelligence Reports