CVE-2024-45257: BYOB Command Injection RCE Vulnerability

CVE-2024-45257 Overview

CVE-2024-45257 is a command injection vulnerability in BYOB (Build Your Own Botnet) 2.0. The flaw resides in the payload build page and is triggered through the freeze function in core/generators.py. Attackers can supply a crafted build parameter to execute arbitrary commands on the server hosting BYOB. The issue is reachable over the network without authentication or user interaction, and a public Metasploit module exists for unauthenticated remote command execution. The vulnerability is categorized under CWE-77: Improper Neutralization of Special Elements used in a Command.

Critical Impact

Unauthenticated attackers can execute arbitrary operating system commands on the BYOB server through the payload build endpoint, enabling full host compromise.

Affected Products

• BYOB (Build Your Own Botnet) 2.0
• BYOB payload build page (core/generators.py, freeze function)
• BYOB deployments exposing the web interface over the network

Discovery Timeline

• 2026-05-08 - CVE-2024-45257 published to NVD
• 2026-05-08 - Last updated in NVD database

Technical Details for CVE-2024-45257

Vulnerability Analysis

The vulnerability is a command injection flaw in the BYOB web interface used to generate malicious payloads. When a user submits a build request, the server invokes the freeze function defined in core/generators.py to package the payload. The build parameter supplied by the requester is incorporated into a shell command without sufficient neutralization of shell metacharacters. An attacker can append additional commands using shell separators, causing the server-side shell to execute arbitrary operating system commands under the privileges of the BYOB process. Because the endpoint does not require authentication, exposure of the build page to untrusted networks results in immediate compromise risk.

Root Cause

The root cause is improper neutralization of special elements used in an OS command [CWE-77]. The freeze routine concatenates user-controlled input into a command string passed to a subprocess shell rather than using safe argument arrays or strict input validation. Shell metacharacters such as ;, &&, |, and backticks remain effective, allowing command chaining.

Attack Vector

The attack vector is network-based and unauthenticated. An attacker sends an HTTP request to the BYOB payload build endpoint with a crafted build parameter containing injected shell syntax. The Metasploit module byob_unauth_rce.rb automates this flow against vulnerable installations. Successful exploitation grants command execution equivalent to the user running the BYOB server process. The EPSS score of approximately 53% (98th percentile) reflects active interest in exploitation tooling for this issue.

No verified code example is published in this advisory. Refer to the Chebuya blog post and the Metasploit BYOB RCE module for technical details on the injection payload structure.

Detection Methods for CVE-2024-45257

Indicators of Compromise

• HTTP requests to the BYOB payload build endpoint containing shell metacharacters such as ;, |, &&, $(), or backticks within the build parameter
• Unexpected child processes spawned by the BYOB Python process (sh, bash, curl, wget, nc, python -c)
• Outbound network connections from the BYOB host to attacker infrastructure shortly after build requests
• Presence of Metasploit byob_unauth_rce User-Agent strings or request signatures in web server logs

Detection Strategies

• Inspect web server and reverse proxy logs for POST requests to the payload build route with non-alphanumeric characters in the build parameter
• Correlate web request telemetry with process-creation events to flag shell processes spawned as children of the BYOB Python interpreter
• Apply intrusion detection signatures that match the request patterns used by the public Metasploit module

Monitoring Recommendations

• Forward web access logs and endpoint process telemetry to a central analytics platform for correlation
• Alert on any execution of sh, bash, cmd.exe, or scripting interpreters originating from the BYOB server process
• Monitor egress traffic from hosts running BYOB for connections to unrecognized external addresses

How to Mitigate CVE-2024-45257

Immediate Actions Required

• Remove BYOB from internet-exposed and untrusted network segments; restrict access to isolated research environments only
• Block external access to the BYOB payload build endpoint at the perimeter firewall or reverse proxy
• Audit hosts running BYOB for signs of prior exploitation, including unexpected scheduled tasks, new users, and outbound connections

Patch Information

BYOB is a research and educational botnet framework maintained at the malwaredllc/byob GitHub repository. No vendor-issued patch is referenced in the CVE record. Operators should track upstream commits to core/generators.py and validate that user input passed to freeze is sanitized or that command construction uses argument arrays instead of shell strings.

Workarounds

• Disable the payload build web interface when not actively in use
• Run BYOB inside a network-isolated virtual machine or container with no inbound exposure and restricted egress
• Enforce authentication and IP allow-listing on any reverse proxy fronting the BYOB web interface
• Replace shell-based subprocess invocations in core/generators.py with subprocess.run using an argument list and shell=False

# Example reverse proxy restriction (nginx) limiting access to the build endpoint
location /build {
    allow 10.0.0.0/24;   # internal research subnet only
    deny all;
    auth_basic "BYOB Lab";
    auth_basic_user_file /etc/nginx/.htpasswd;
    proxy_pass http://127.0.0.1:5000;
}