CVE-2021-27436 Cross-site scripting in Advantech WebAccess/SCADA

Medium 6.1 Published 18 Mar 2021 Updated 3 Aug 2024

Attackers can inject malicious scripts into WebAccess/SCADA to hijack user sessions and redirect victims, requiring an upgrade to mitigate.

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-2021-27436?

CVE-2021-27436 is a medium-severity cross-site scripting vulnerability in Advantech WebAccess/SCADA, published on 18 Mar 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

WebAccess/SCADA Versions 9.0 and prior is vulnerable to cross-site scripting, which may allow an attacker to send malicious JavaScript code to an unsuspecting user, which could result in hijacking of the user’s cookie/session tokens, redirecting the user to a malicious webpage and performing unintended browser actions.

Weakness: CWE-79

Which versions are affected by CVE-2021-27436?

It affects 1 product.

Products include Advantech Webaccess\/Scada.

How do I fix CVE-2021-27436?

No fix has been published for CVE-2021-27436 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-2021-27436 being exploited?

There is no known exploitation of CVE-2021-27436 in the wild and no public exploit code.

Sources

Also known as GHSA-h79w-h983-cvxf.