CVE-2020-23533

Name: CVE-2020-23533
Creator: NVD / NIST
Published: 2021-04-06T16:15:14.863+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 0.92%

Last modified Jun 17, 2026

CVE-2020-23533 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 0.92% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

0.92%

55.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-347

Affected Software

Vendor	Product	Versions
Unionpayintl	Union Pay	<= 1.2.0

References

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

Timeline

Published: Apr 6, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2020-23533?

How severe is CVE-2020-23533?

CVE-2020-23533 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.92% probability of exploitation in the next 30 days.

How do I fix CVE-2020-23533?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2020-23533?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST