CVE-2021-21800 Cross-site scripting in Advantech

Critical 9.6 Published 16 Jul 2021 Updated 3 Aug 2024

Cross-site scripting in Advantech R-SeeNet allows attackers to execute arbitrary JavaScript in a victim's browser via a crafted URL.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2021-21800?

CVE-2021-21800 is a critical cross-site scripting vulnerability in Advantech, published on 16 Jul 2021. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

Cross-site scripting vulnerabilities exist in the ssh_form.php script functionality of Advantech R-SeeNet v 2.4.12 (20.10.2020). If a user visits a specially crafted URL, it can lead to arbitrary JavaScript code execution in the context of the targeted user’s browser. An attacker can provide a crafted URL to trigger this vulnerability.

Weakness: CWE-79

Which versions are affected by CVE-2021-21800?

It affects 1 product.

Products include Advantech R-Seenet.

How do I fix CVE-2021-21800?

No fix has been published for CVE-2021-21800 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-2021-21800 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21800 exists.

Public exploit code: 1 Nuclei template.

Sources

Also known as GHSA-xhc7-qp6w-xmwm.