CVE-2020-23533

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-06 · updated 2026-06-17
Weakness: CWE-347

Description

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: through 1.2.0

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/
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

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