Description
Scratch Addons is a WebExtension that supports both Chrome and Firefox. Scratch Addons before version 1.3.2 is vulnerable to DOM-based XSS. If the victim visited a specific website, the More Links addon of the Scratch Addons extension used incorrect regular expression which caused the HTML-escaped values to be unescaped, leading to XSS. Scratch Addons version 1.3.2 fixes the bug. The extension will be automatically updated by the browser. More Links addon can be disabled via the option of the extension.
References (4)
Core 4
Core References
Patch, Third Party Advisory x_refsource_confirm
https://github.com/ScratchAddons/ScratchAddons/security/advisories/GHSA-6qfq-px3r-xj4p
Patch, Third Party Advisory x_refsource_misc
https://github.com/ScratchAddons/ScratchAddons/commit/b9a52d6532c8514254c7cc1d8e18710dbedc41ff
Third Party Advisory x_refsource_misc
https://github.com/ScratchAddons/ScratchAddons/blob/a471893df403f86c9182970678175d4772a0690c/addons/more-links/userscript.js#L15
Release Notes, Third Party Advisory x_refsource_misc
https://github.com/ScratchAddons/ScratchAddons/releases/tag/v1.3.2
Scores
CVSS v3
7.6
EPSS
0.0028
EPSS Percentile
51.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:N
Details
CWE
CWE-79
Status
published
Products (1)
scratchaddons/scratch_addons
< 1.3.2
Published
Nov 23, 2020
Tracked Since
Feb 18, 2026