CVE-2025-34237 Advantech WebAccess/VPN < 1.1.5 Stored XSS via StandaloneVpnClientsController.addStandaloneVpnClientAction()
Attackers can inject malicious scripts into the WebAccess/VPN interface, potentially hijacking user sessions or executing code in victims' browsers.
- 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-2025-34237?
CVE-2025-34237 is a medium-severity cross-site scripting vulnerability in Advantech WebAccess/VPN, published on 6 Nov 2025. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Advantech WebAccess/VPN versions prior to 1.1.5 contain a stored cross-site scripting (XSS) vulnerability via StandaloneVpnClientsController.addStandaloneVpnClientAction(). Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.
Weakness: CWE-79
Which versions are affected by CVE-2025-34237?
It affects 1 product.
Products include Advantech Webaccess\/Vpn.
How do I fix CVE-2025-34237?
No fix has been published for CVE-2025-34237 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-2025-34237 being exploited?
There is no known exploitation of CVE-2025-34237 in the wild and no public exploit code.
Other vulnerabilities in Advantech WebAccess/VPN
- CVE-2025-34239 Advantech WebAccess/VPN < 1.1.5 Command Injection in AppManagementController.appUpgradeAction()
- CVE-2025-34240 Advantech WebAccess/VPN < 1.1.5 SQL Injection via AppManagementController.appUpgradeAction()
- CVE-2025-34242 Advantech WebAccess/VPN < 1.1.5 SQL Injection via AjaxNetworkController.ajaxAction()
- CVE-2025-34238 Path traversal in WebAccess/VPN
- CVE-2025-34236 Advantech WebAccess/VPN < 1.1.5 Stored XSS via NetworksController.addNetworkAction()
Sources
Also known as GHSA-c27p-92mm-fc82.