CVE-2020-23533

7.5 highEPSS 0.9%

High (7.5) in unionpayintl union pay. 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.

Severity

CVSS 3.1

7.5 high

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

EPSS: 0.9% chance of exploitation in the next 30 days; higher than 60% of CVEs (scores of 2026-10-31)
CWE: CWE-347
Published: 2021-04-06
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

unionpayintl:union_pay

References

http://mobitec.ie.cuhk.edu.hk/cve_2020/
https://cwe.mitre.org/data/definitions/347.html
https://www.dropbox.com/s/6smwnbrp0kgsgrc/poc_code.py?dl=0
https://www.dropbox.com/s/czbkdr73tclq2nr/UnionPay_Vulnerability_Report.txt?dl=0
http://mobitec.ie.cuhk.edu.hk/cve_2020/

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