CVE-2020-26239 Cross-Site Scripting in Scratch browser addons
A DOM-based XSS vulnerability in the Scratch Addons browser extension allows attackers to execute arbitrary scripts when a victim visits a malicious website.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2020-26239?
CVE-2020-26239 is a high-severity cross-site scripting vulnerability in ScratchAddons, published on 23 Nov 2020. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2020-26239?
It affects 1 product.
Products include Scratchaddons Scratch Addons.
How do I fix CVE-2020-26239?
No fix has been published for CVE-2020-26239 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2020-26239 being exploited?
There is no known exploitation of CVE-2020-26239 in the wild and no public exploit code.
Sources
Also known as GHSA-6qfq-px3r-xj4p.