CVE-2021-41038 Improper Verification of Communication Channel in @theia/plugin-ext
Attackers can hijack Webview contents in Eclipse Theia via postMessage, potentially executing malicious code or bypassing security controls.
- 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
- Available
What is CVE-2021-41038?
CVE-2021-41038 is a medium-severity cross-site scripting vulnerability in @theia/plugin-ext, published on 10 Nov 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
In versions of the @theia/plugin-ext component of Eclipse Theia prior to 1.18.0, Webview contents can be hijacked via postMessage().
Weakness: CWE-940
Which versions are affected by CVE-2021-41038?
2 open source packages ship an affected version, including @theia/plugin-ext. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
@theia/plugin-ext npm | All versions | 1.18.0 |
@theia/plugin-ext npm | All versions | 1.18.0 |
Products include Eclipse Theia.
How do I fix CVE-2021-41038?
Upgrade @theia/plugin-ext to 1.18.0 or later.
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-2021-41038 being exploited?
There is no known exploitation of CVE-2021-41038 in the wild and no public exploit code.
Other vulnerabilities in @theia/plugin-ext
- CVE-2021-34436 XML external entity in Eclipse Theia
- CVE-2020-27224 Cross-site Scripting (XSS) in Eclipse Theia
- CVE-2026-60009 File upload in Eclipse Theia
- CVE-2021-34435 Remote code execution in Eclipse Theia
- CVE-2026-44688 [Eclipse Theia] Indirect Prompt Injection via Adversarial Workspace File and Directory Names in AI Chat
Sources
Also known as GHSA-w6v7-w58j-pg5r.