CVE-2024-33434

Executive Summary

CVE-2024-33434 is a critical code injection vulnerability in tiagorlampert CHAOS v5.0.1, a remote administration tool. The flaw resides in the unsafe concatenation of the filename argument into the buildStr string without any sanitization or filtering. This allows a remote attacker to execute arbitrary code on the target system. The vulnerability affects versions prior to commit 1b451cf62582295b7225caf5a7b506f0bad56f6b. No public exploit code or proof-of-concept is currently available, but the risk is high due to the nature of the software (remote admin tool) and the ease of exploitation.

CVSS Breakdown & Threat Level

The CVSS score is currently 0.0, indicating that no official CVSS vector has been assigned by NVD. However, based on the vulnerability description, a reasonable assessment would be:

• Attack Vector (AV): Network (N) – The attacker can exploit this remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – The exploit does not affect other components.
• Confidentiality (C): High (H) – Arbitrary code execution can lead to data theft.
• Integrity (I): High (H) – Code execution can modify system files.
• Availability (A): High (H) – Code execution can disrupt services.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Estimated Score: 9.8 (Critical)

Threat Level: Critical. The vulnerability allows unauthenticated remote code execution in a remote administration tool, which is a prime target for attackers.

Deep Dive & Mechanics

The vulnerability is a classic code injection (CWE-94) in the CHAOS remote administration tool. The filename parameter is concatenated directly into a buildStr string that is likely used to construct a command or script. Without sanitization, an attacker can inject arbitrary commands or code by providing a malicious filename value.

For example, if the buildStr is something like "build " + filename, an attacker could set filename to "; malicious_command" to execute arbitrary code. The exact injection point depends on the context (e.g., shell command, script execution, or code compilation).

The vulnerability exists in versions before commit 1b451cf62582295b7225caf5a7b506f0bad56f6b. The patch likely introduces input validation or escaping of the filename parameter.

Vulnerable vs. Patched Code

Vulnerable Code (before commit 1b451cf):

# Example vulnerable code (conceptual)
def build(filename):
    buildStr = "build " + filename  # Unsafe concatenation
    os.system(buildStr)

Patched Code (after commit 1b451cf):

# Example patched code (conceptual)
import shlex

def build(filename):
    safe_filename = shlex.quote(filename)  # Sanitize input
    buildStr = "build " + safe_filename
    os.system(buildStr)

The patch uses shlex.quote() to escape shell metacharacters, preventing injection.

Exploitation & Lab Setup

Red Team (Exploitation)

Since no public exploit is available, a proof-of-concept can be crafted. The attacker would send a crafted request to the CHAOS server with a malicious filename parameter.

Example Payload:

# Assuming the vulnerable endpoint is /build?filename=
curl "http://target:port/build?filename=;id"

If successful, the id command would execute on the server.

Lab Setup:

1. Download CHAOS v5.0.1 from the official repository.
2. Set up a test environment (e.g., Docker container).
3. Run the vulnerable version.
4. Send the malicious request and observe the output.

Blue Team (Defense)

Detection:

• Monitor for unusual filename parameters in HTTP requests to CHAOS endpoints.
• Look for shell metacharacters (e.g., ;, |, &, `) in the filename field.
• Use Web Application Firewall (WAF) rules to block such patterns.

Mitigation:

• Immediately update to the patched version.
• If patching is not possible, implement input validation on the filename parameter.
• Restrict network access to the CHAOS server.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to CHAOS endpoints with filename containing shell metacharacters.
  • Outbound connections from the CHAOS server to unknown IPs (post-exploitation).
• File IOCs:
  • Unexpected files in the CHAOS installation directory.
  • Modified system binaries or scripts.
• Process IOCs:
  • Unusual child processes spawned by the CHAOS process (e.g., cmd.exe, /bin/sh).

Detection Engineering

YARA Rule

rule CVE_2024_33434_CodeInjection {
    meta:
        description = "Detects attempts to exploit CVE-2024-33434 in CHAOS v5.0.1"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-33434"
    strings:
        $suspicious = /filename=[^&]*[;|&`$(){}]/
    condition:
        $suspicious
}

Sigma Rule

title: CVE-2024-33434 CHAOS Code Injection Attempt
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects HTTP requests with malicious filename parameter targeting CHAOS
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: "/build?filename="
        c-uri|re: "filename=[^&]*[;|&`$(){}]"
    condition: selection
falsepositives:
    - Legitimate use of special characters in filenames (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-33434 CHAOS Code Injection Attempt"; flow:to_server; content:"/build?filename="; http_uri; pcre:"/filename=[^&]*[;|&`$(){}]/Ri"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Update CHAOS to the latest patched version (commit 1b451cf62582295b7225caf5a7b506f0bad56f6b or later).
2. Workaround: If patching is not possible, implement input validation on the filename parameter. Reject any input containing shell metacharacters.
3. Network Segmentation: Restrict access to the CHAOS server to trusted IPs only.
4. Monitoring: Enable logging and monitoring for suspicious activity as described in the Detection Engineering section.
5. Incident Response: If exploitation is suspected, isolate the affected system and conduct a forensic investigation.

Valters IT
DevSecOps & Cyber Threat Intelligence Expert