CVE-2025-66224 Overview
CVE-2025-66224 is a command injection vulnerability in OrangeHRM, an open-source human resource management (HRM) system. The flaw affects versions 5.0 through 5.7 and resides in the mail configuration and delivery workflow. User-controlled values flow directly into the system's sendmail command without sanitization. Authenticated attackers can invoke unintended sendmail behaviors during email processing, including writing files to the server. When written files land in web-accessible directories, attackers achieve remote code execution. The issue is tracked under CWE-94: Improper Control of Generation of Code and is patched in version 5.8.
Critical Impact
Authenticated attackers can write attacker-controlled files to the server through the mail-sending logic, enabling remote code execution when files land in web-accessible paths.
Affected Products
- OrangeHRM version 5.0
- OrangeHRM versions 5.1 through 5.6
- OrangeHRM version 5.7
Discovery Timeline
- 2025-11-29 - CVE-2025-66224 published to NVD
- 2025-12-03 - Last updated in NVD database
Technical Details for CVE-2025-66224
Vulnerability Analysis
The vulnerability resides in OrangeHRM's mail configuration and delivery workflow. The application constructs operating system command strings for sendmail by concatenating user-supplied input without sanitization. Because sendmail accepts numerous command-line switches that alter its behavior, attacker-controlled values reaching this command path can change how the binary operates during normal mail processing.
One consequence of this design is the ability to direct sendmail to write files on the host. When OrangeHRM is deployed with mail handling that places output in directories served by the web server, the attacker controls both the file content and its location. This converts a mail-handling routine into an arbitrary file write primitive and, in many production deployments, into remote code execution.
Root Cause
The root cause is improper neutralization of input used in command construction, classified as CWE-94: Improper Control of Generation of Code. The mail-sending logic builds shell-level command strings from values that originate in user-controllable configuration fields. No constraint, escaping, or allowlist is applied before the values reach the command execution path.
Attack Vector
An authenticated user with access to mail configuration submits values designed to be interpreted as additional sendmail arguments. During subsequent mail delivery, OrangeHRM invokes sendmail with the attacker-influenced command line. The attacker triggers file writes containing controlled content. If the destination path is reachable through the web server, the attacker requests the file and executes the embedded payload under the web service account.
No verified public proof-of-concept code has been released. The vendor advisory at OrangeHRM GHSA-2w7w-h5wv-xr55 describes the issue and the fix in version 5.8.
Detection Methods for CVE-2025-66224
Indicators of Compromise
- Unexpected files written under web-accessible directories such as public/, web/, or document roots, particularly PHP files with recent timestamps.
- sendmail process invocations containing argument flags supplied through application configuration values rather than internal defaults.
- Outbound mail activity correlated with file creation events on the OrangeHRM host.
- HTTP requests to newly created files immediately following changes to mail configuration.
Detection Strategies
- Monitor process creation events for the OrangeHRM service account spawning sendmail with arguments that include file paths writable by the web server.
- Alert on web shells or PHP files appearing in OrangeHRM deployment directories that were not part of the original installation.
- Inspect application audit logs for modifications to mail server, sender, or related configuration fields followed by outbound mail.
Monitoring Recommendations
- Enable file integrity monitoring across the OrangeHRM document root and any directory served by the web server.
- Capture and retain process command-line arguments for sendmail and related mail transport binaries.
- Centralize OrangeHRM application logs and correlate configuration changes with subsequent process and filesystem events.
How to Mitigate CVE-2025-66224
Immediate Actions Required
- Upgrade OrangeHRM to version 5.8, which contains the patch for CVE-2025-66224.
- Audit mail configuration fields for values containing shell metacharacters or sendmail switches such as -O, -C, or -X.
- Review web-accessible directories for unexpected files created since the deployment was first exposed.
- Restrict administrative access to mail configuration to a minimum set of accounts and enforce strong authentication.
Patch Information
The vulnerability is fixed in OrangeHRM 5.8. The fix removes the unsanitized flow of user input into the sendmail command construction. Refer to the OrangeHRM GitHub Security Advisory GHSA-2w7w-h5wv-xr55 for vendor guidance and release notes.
Workarounds
- Limit network exposure of OrangeHRM administrative interfaces to trusted management networks until patching is complete.
- Run the OrangeHRM PHP process under an account that lacks write access to web-served directories.
- Configure the web server to deny execution of dynamic content in upload and temporary directories.
- Replace direct sendmail invocation with an SMTP relay where supported by the deployment.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
