CVE-2022-40771: XML External Entity (XXE) Vulnerability in Zoho ManageEngine ServiceDesk Plus Versions 13010 and Below, Leading to Information Disclosure

Zoho ManageEngine ServiceDesk Plus is a popular IT help desk software used by organizations to manage their IT infrastructure. Recently, a critical vulnerability, identified as CVE-2022-40771, has been discovered in Zoho ManageEngine ServiceDesk Plus versions 13010 and below. This vulnerability allows attackers to perform an XML External Entity (XXE) attack that may lead to sensitive information disclosure.

What is an XML External Entity (XXE) Attack?

An XML External Entity attack is a type of security vulnerability that occurs when an XML parser, used within a web application, is tricked into processing XML data from an untrusted source. This can lead to unauthorized access to sensitive data, and in some cases, allows attackers to gain control of the server or perform a Denial of Service (DoS) attack.

Exploit Details

The vulnerability (CVE-2022-40771) impacts the file upload functionality of Zoho ManageEngine ServiceDesk Plus, which is used for various tasks, including updating user profiles and attaching files to incident tickets. Due to the improper handling of XML data, an attacker can upload an XML file containing malicious external entity references, causing the server to process the XML data without proper sanitization. Consequently, this can lead to unauthorized access to sensitive information stored on the server.

To exploit this vulnerability, an attacker can create a specially-crafted XML file as shown below

<?xml version="1." encoding="UTF-8"?>
<!DOCTYPE exploit [
<!ENTITY xxe SYSTEM "file:///etc/passwd">
]>
<exploit>&xxe;</exploit>

This XML file contains an external entity reference to the server's /etc/passwd file, which typically stores sensitive user account information. When uploaded to the vulnerable application, the XML parser processes the external entity reference, resulting in the disclosure of the /etc/passwd file content.

Mitigation

Users of Zoho ManageEngine ServiceDesk Plus are advised to update their software to the latest version (13011 or later) available on the vendor's website. This update addresses the vulnerability by implementing proper sanitization of XML data received from untrusted sources.

In addition, developers can implement the following best practices in their applications to prevent XXE attacks:

Implement proper input validation and sanitization mechanisms for handling untrusted data.

4. Regularly review and update software dependencies and libraries to minimize potential security risks.

Conclusion

The CVE-2022-40771 vulnerability in Zoho ManageEngine ServiceDesk Plus can lead to significant information disclosure if exploited by attackers. Organizations should update their software to the latest version and implement security best practices to safeguard their IT infrastructure. In addition, staying informed about new vulnerabilities and potential threats helps organizations to take proactive measures in securing their software and systems.

Timeline

Published on: 11/23/2022 18:15:00 UTC
Last modified on: 11/29/2022 20:19:00 UTC