Overview
This article details a critical vulnerability, identified as CVE-2025-66224, affecting OrangeHRM, a widely used human resource management system. Versions 5.0 to 5.7 are vulnerable to an input-neutralization flaw in the mail configuration and delivery workflow. This allows attackers to potentially write arbitrary files on the server, which in turn could lead to Remote Code Execution (RCE) if the written files are accessible via the web.
Technical Details
The vulnerability stems from the lack of proper sanitization of user-controlled input within the mail-sending logic. Specifically, when configuring and sending emails, user-provided values are directly incorporated into the system’s `sendmail` command. This unvalidated input allows attackers to manipulate `sendmail`’s behavior. By crafting malicious email configurations, an attacker can potentially write files to arbitrary locations on the server. For example, the `-oQ` option, allowing to specify an alternate mail queue directory, could be abused to write files in web-accessible locations. If the attacker can write a file containing executable code (e.g., a PHP script) to a web-accessible directory, they can then execute that code by accessing the file through a web browser, leading to Remote Code Execution.
The core issue is the construction of OS-level command strings using unsanitized input. This directly violates secure coding principles and creates a significant security risk.
CVSS Analysis
The CVE information indicates a N/A severity and CVSS score. However, based on the description, the impact of this vulnerability is potentially very high. A successful exploit could lead to complete compromise of the OrangeHRM system and potentially the underlying server. A full CVSS analysis should be conducted with a focus on attack complexity, privileges required, user interaction and scope in order to get the correct score. An expert should calculate this based on individual environments.
Possible Impact
- Arbitrary File Write: Attackers can write files to arbitrary locations on the server, potentially overwriting existing files or creating new ones.
- Remote Code Execution (RCE): If attackers can write executable files (e.g., PHP scripts) to web-accessible directories, they can execute arbitrary code on the server.
- Data Breach: RCE can be leveraged to access sensitive data stored in the OrangeHRM system or on the server.
- System Takeover: Complete control of the OrangeHRM system and potentially the underlying server.
- Denial of Service (DoS): Writing files to critical system locations could disrupt the operation of the server.
Mitigation or Patch Steps
The vulnerability is patched in OrangeHRM version 5.8. Users of versions 5.0 to 5.7 are strongly advised to upgrade to version 5.8 or later as soon as possible.
If upgrading is not immediately feasible, consider implementing the following temporary mitigations:
- Restrict Access: Limit access to the mail configuration settings to only trusted administrators.
- Input Validation: Implement strict input validation and sanitization on all user-provided values related to email configuration, particularly those used in the `sendmail` command. Specifically validate that the parameters don’t contain shell meta characters, escape or remove them.
- Web Server Hardening: Ensure that web server configurations are hardened to prevent the execution of arbitrary files in web-accessible directories (e.g., by configuring proper file permissions and disabling script execution in upload directories).
