CVE-2021-43532

2021-12-0800:00:00

ubuntu.com

firefox

image link

authentication

vulnerability

redirects

content security policy

authentication tokens

CVSS2

5.8

Attack Vector

NETWORK

Attack Complexity

MEDIUM

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

NONE

AV:N/AC:M/Au:N/C:P/I:P/A:N

CVSS3

6.1

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

LOW

Integrity Impact

LOW

Availability Impact

NONE

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

EPSS

0.001

Percentile

36.7%

JSON

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.