CVE-2026-15657 in foreUP
Summary
by MITRE • 07/30/2026
A vulnerability in the foreUP customer REST API allows any authenticated user to read cleartext payment-processor merchant credentials in the response body.
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Analysis
by VulDB Data Team • 07/30/2026
This vulnerability represents a critical security flaw in the foreUP customer REST API that enables unauthorized access to sensitive payment processing information. The issue stems from improper access control mechanisms within the API's response handling, where authenticated users can retrieve cleartext merchant credentials without proper authorization checks. This configuration violates fundamental security principles and creates significant risk for both the organization and its customers who rely on secure payment processing.
The technical implementation flaw occurs when the API endpoint returns sensitive credential information in plaintext format within the response body, regardless of the requesting user's privileges or role. This represents a classic case of insufficient authorization controls and inadequate data protection measures. According to the CWE database, this vulnerability aligns with CWE-284 Access Control Issues, specifically manifesting as improper access control where the system fails to enforce proper authorization checks before exposing sensitive data. The flaw essentially creates a path for privilege escalation through data exposure, allowing any authenticated user to obtain information they should not have access to.
The operational impact of this vulnerability extends beyond immediate credential theft, potentially enabling attackers to impersonate merchants, conduct fraudulent transactions, or gain unauthorized access to payment processing systems. The cleartext nature of the exposed credentials means that even if network traffic is intercepted, the sensitive information remains easily readable without additional decryption efforts. This vulnerability directly relates to ATT&CK technique T1566 Credential Access through the exploitation of API access control weaknesses and could facilitate further attacks including lateral movement within payment processing environments or data exfiltration from merchant accounts.
Organizations should implement immediate mitigations including proper access control enforcement, credential obfuscation techniques, and comprehensive logging of API access attempts. The API response handling must be modified to ensure that sensitive merchant credentials are only returned to authorized administrative users with appropriate privileges. Additionally, implementing token-based authentication mechanisms and encrypting sensitive data in transit and at rest would significantly reduce the attack surface. Regular security testing including penetration testing and vulnerability scanning should be conducted to identify similar access control issues within the API ecosystem. The implementation of proper input validation and output encoding techniques would prevent unauthorized data exposure while maintaining system functionality for legitimate users requiring appropriate access levels.