CVE-2021-33839

Name: CVE-2021-33839
Creator: NVD / NIST
Published: 2021-06-04T00:15:07.377+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 2.77%

Last modified Jun 17, 2026

CVE-2021-33839 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. Luca through 1.7.4 on Android allows remote attackers to obtain sensitive information about COVID-19 tracking because the QR code of a Public Location can be intentionally confused with the QR code of a Private Meeting.. EPSS estimates a 2.77% chance of exploitation in the next 30 days.

Description

Luca through 1.7.4 on Android allows remote attackers to obtain sensitive information about COVID-19 tracking because the QR code of a Public Location can be intentionally confused with the QR code of a Private Meeting.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

2.77%

84.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-200

Affected Software

Vendor	Product	Versions
Luca-App	Luca	<= 1.7.4

References

https://github.com/mame82/misc/blob/master/luca_traceIds.mdThird Party Advisory
https://luca-app.de/securityoverview/properties/objectives.htmlVendor Advisory
https://twitter.com/patrick_hennig/status/1387738281757061125Third Party Advisory
https://youtu.be/jWyDfEB0m08Exploit, Third Party Advisory
https://github.com/mame82/misc/blob/master/luca_traceIds.mdThird Party Advisory
https://luca-app.de/securityoverview/properties/objectives.htmlVendor Advisory
https://twitter.com/patrick_hennig/status/1387738281757061125Third Party Advisory
https://youtu.be/jWyDfEB0m08Exploit, Third Party Advisory

Timeline

Published: Jun 4, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-33839?

How severe is CVE-2021-33839?

CVE-2021-33839 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 2.77% probability of exploitation in the next 30 days.

How do I fix CVE-2021-33839?

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-2021-33839?

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

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Source: NVD / NIST