CVE-2021-43532

Name: CVE-2021-43532
Creator: NVD / NIST
Published: 2021-12-08T22:15:09.367+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 6.1/10EPSS 0.53%

Last modified Jun 17, 2026

CVE-2021-43532 is a medium-severity vulnerability rated 6.1/10 on the CVSS scale. The 'Copy Image Link' context menu action would copy the final image URL after redirects. By embedding an image that triggered authentication flows - in conjunction with a Content Security Policy that stopped a redirection chain in the middle - the final image URL could be one that contained an authentication token used to takeover a user account. EPSS estimates a 0.53% chance of exploitation in the next 30 days.

Description

The 'Copy Image Link' context menu action would copy the final image URL after redirects. By embedding an image that triggered authentication flows - in conjunction with a Content Security Policy that stopped a redirection chain in the middle - the final image URL could be one that contained an authentication token used to takeover a user account. If a website tricked a user into copy and pasting the image link back to the page, the page would be able to steal the authentication tokens. This was fixed by making the action return the original URL, before any redirects. This vulnerability affects Firefox < 94.

Metrics

CVSS 3.1

6.1/10

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

EPSS Probability

0.53%

40.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 94.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1719203Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory
https://bugzilla.mozilla.org/show_bug.cgi?id=1719203Issue Tracking, Permissions Required, Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2021-48/Vendor Advisory

Timeline

Published: Dec 8, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-43532?

How severe is CVE-2021-43532?

CVE-2021-43532 has a CVSS score of 6.1/10 (MEDIUM severity). The EPSS model estimates a 0.53% probability of exploitation in the next 30 days.

How do I fix CVE-2021-43532?

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-2021-43532?

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

Scan your code now

Source: NVD / NIST