npm PraisonAI utility-tools.shell() Allowlist Bypass via Shell Chaining (GHSA-5jv7-2mjm-h6qj)

The npm package praisonai has been identified with a command injection vulnerability (GHSA-5jv7-2mjm-h6qj) affecting versions 1.5.1 through 1.7.1. The utility-tools.shell() helper, located in dist/tools/utility-tools.js, is designed to execute "safe read-only commands" by checking only the first whitespace-delimited token against an allowlist (e.g., ls, cat, echo). However, the function then passes the entire input string to Node.js's child_process.exec(), which executes it via a system shell. This policy/parser differential allows an attacker to prefix a malicious command with an allowed command and shell metacharacters (e.g., echo ok; malicious_command), bypassing the intended allowlist and executing arbitrary commands with the PraisonAI process's privileges. This flaw enables potential file system access, network exfiltration, or denial of service within applications using this vulnerable library.

Attack Chain

1. Initial Access: An attacker identifies an application or service that integrates the praisonai library (versions 1.5.1-1.7.1) and exposes functionality that processes user-controlled input through the vulnerable utility-tools.shell() helper.
2. Command Crafting: The attacker crafts a malicious command string. This string starts with a command found in utility-tools.shell()'s safeCommands allowlist (e.g., echo, ls) followed by a shell metacharacter (e.g., ;, &&, |) and the desired arbitrary command (e.g., cat /etc/passwd, curl evil.com).
3. Vulnerable Function Call: The crafted malicious command string is submitted as input to the vulnerable application. The application, in turn, passes this string to the praisonai's utility-tools.shell() function.
4. Allowlist Check Bypass: The utility-tools.shell() function performs its safety check by splitting the input string by whitespace and validating only the first token (e.g., echo) against its internal safeCommands allowlist. Since the first token is allowed, the check passes.
5. Shell Execution: The function proceeds to pass the entire, unaltered malicious command string (e.g., echo; cat /etc/passwd) to Node.js's child_process.exec().
6. Arbitrary Command Execution: child_process.exec() invokes the system's default shell (e.g., sh -c on Linux, cmd.exe /c on Windows), which interprets the full string. The shell executes the initial allowed command, then, upon encountering the shell metacharacter, proceeds to execute the appended arbitrary command (e.g., cat /etc/passwd).
7. Impact: The arbitrary command is executed with the privileges of the PraisonAI application process, potentially leading to sensitive data exposure, file modification, network communication, or system disruption, depending on the command and process context.

Impact

If an application or service exposes the vulnerable utility-tools.shell() helper to untrusted input, the safe-command allowlist becomes ineffective. Attackers can execute arbitrary shell commands with the PraisonAI process privileges. The specific consequences are determined by the embedding application's context and permissions, but can include unauthorized reading of sensitive files and secrets (e.g., credentials, configuration files), modification of files or application state, invocation of local tools, network exfiltration of data if egress is permitted, and denial of service through resource-intensive commands. While no specific victim numbers are available, the broad applicability of Node.js applications means any sector using praisonai between versions 1.5.1 and 1.7.1 could be affected.

Recommendation

• Patch Vulnerable Library: Immediately update praisonai to a version higher than 1.7.1 (or explicitly prior to 1.5.1) to address GHSA-5jv7-2mjm-h6qj. The advisory suggests avoiding exec(command) for policy-checked strings and instead using execFile() or spawn() with shell: false.
• Deploy Detection Rules: Implement the provided Sigma rules to detect patterns indicative of this exploitation on both Linux/macOS and Windows hosts that run Node.js applications.
• Review Code for Vulnerable Usage: Developers should review their codebase for any instances where praisonai/dist/tools/utility-tools.js is imported and its shell() function is called with user-controlled input. Refactor such calls to ensure input is properly sanitized or leverage safer alternatives as described in the "Suggested Fix" section of the advisory (GHSA-5jv7-2mjm-h6qj).
• Enable Detailed Process Logging: Ensure process_creation logging (e.g., via Sysmon on Windows, Auditd/eBPF on Linux) is enabled and configured to capture full command lines, parent-child process relationships, and image paths to effectively utilize the provided Sigma rules.