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.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-23533
Reference (s):
- http://mobitec.ie.cuhk.edu.hk/cve_2020/
- https://www.dropbox.com/s/6smwnbrp0kgsgrc/poc_code.py?dl=0
- https://www.dropbox.com/s/czbkdr73tclq2nr/UnionPay_Vulnerability_Report.txt?dl=0