CVE-2020-23533: Unionpayintl Union Pay

High severity, CVSS 7.5. EPSS: 0.9% chance of exploitation in the next 30 days.

Union Pay up to 1.2.0, for web based versions contains a CWE-347: Improper Verification of Cryptographic Signature vulnerability, allows attackers to shop for free in merchants' websites and mobile apps, via a crafted authentication code (MAC) which is generated based on a secret key which is NULL.

Affected products

• Unionpayintl Union Pay: up to and including 1.2.0

Published 2021-04-06. Last modified 2026-06-17.