CVE-2018-15656 in SureMDM
Summary
by MITRE
An issue was discovered in the registration API endpoint in 42Gears SureMDM before 2018-11-27. An attacker can submit a GET request to /api/register/:email, where :email is a base64 encoded e-mail address, to receive confirmation as to whether a user account exists in the system with the specified e-mail address. The request must be made with an "apiKey" value in the "ApiKey" header.
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Analysis
by VulDB Data Team • 07/04/2023
This vulnerability in 42Gears SureMDM represents a critical information disclosure flaw that exposes user account enumeration capabilities to unauthorized attackers. The issue exists within the registration API endpoint where the system fails to properly validate or restrict access to account existence verification functionality. When an attacker submits a GET request to the specific endpoint /api/register/:email with a base64 encoded email address, the system responds with information that confirms or denies the existence of that email address within the user database. This behavior fundamentally violates the principle of least privilege and creates a direct avenue for account enumeration attacks that can be leveraged to identify valid user accounts.
The technical implementation of this vulnerability stems from inadequate input validation and access control mechanisms within the API endpoint. The system accepts an apikey parameter in the ApiKey header but fails to properly authenticate or authorize the request before performing the account existence check. This design flaw allows any attacker who possesses a valid apikey to perform account enumeration across potentially thousands of email addresses, effectively creating a user account fingerprinting capability. The vulnerability specifically affects versions prior to 2018-11-27, indicating that this was a known issue that required a specific patch to address the improper access control implementation.
The operational impact of this vulnerability extends beyond simple information disclosure to enable more sophisticated attack vectors including targeted credential stuffing, account takeover attempts, and social engineering operations. Attackers can systematically test large lists of email addresses against the endpoint to build comprehensive user account databases, which can then be used to launch more effective phishing campaigns or brute force attacks against the identified accounts. This enumeration capability undermines the security posture of organizations using the platform, as it provides attackers with a reliable method to identify legitimate user accounts within the system. The vulnerability aligns with CWE-200, which addresses information exposure, and represents a clear violation of the principle of least privilege in API security design.
Organizations should implement immediate mitigations including strengthening API access controls, implementing rate limiting on registration endpoints, and ensuring that account existence verification responses do not distinguish between valid and invalid email addresses. The fix should involve modifying the API endpoint to return consistent responses regardless of whether an account exists, thereby preventing account enumeration. Additionally, organizations should review their API security configurations to ensure that sensitive operations do not expose information about system internals or user populations. This vulnerability demonstrates the importance of proper access control implementation and the need for comprehensive API security testing, particularly focusing on authentication and authorization mechanisms. The remediation approach should follow ATT&CK framework guidance for API security by ensuring that all API endpoints properly validate and restrict access based on proper authentication and authorization controls.