CVE-2020-36321 Directory traversal in development mode handler in Vaadin 14 and 15-17
Attackers can read arbitrary files outside the intended directory via improper URL validation in the development mode handler.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2020-36321?
CVE-2020-36321 is a medium-severity path traversal vulnerability in Vaadin, published on 23 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Improper URL validation in development mode handler in com.vaadin:flow-server versions 2.0.0 through 2.4.1 (Vaadin 14.0.0 through 14.4.2), and 3.0 prior to 5.0 (Vaadin 15 prior to 18) allows attacker to request arbitrary files stored outside of intended frontend resources folder.
Weakness: CWE-22
Which versions are affected by CVE-2020-36321?
4 open source packages ship an affected version, including com.vaadin:flow-server. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
com.vaadin:flow-server Maven | From 2.0.0 | 2.4.2 |
com.vaadin:flow-server Maven | From 2.0.0 | 2.4.2 |
com.vaadin:flow-server Maven | From 3.0.0 | 5.0.0 |
com.vaadin:flow-server Maven | From 3.0.0 | 5.0.0 |
Products include Vaadin Flow, Vaadin Vaadin.
How do I fix CVE-2020-36321?
Upgrade com.vaadin:flow-server to a fixed version for your release line: 2.4.2 or 5.0.0.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2020-36321 being exploited?
There is no known exploitation of CVE-2020-36321 in the wild and no public exploit code.
Other vulnerabilities in Vaadin
- CVE-2021-31407 Server classes and resources exposure in OSGi applications using Vaadin 12-14 and 19
- CVE-2021-31405 Regular expression denial of service (ReDoS) in EmailField component in Vaadin 14 and 15-17
- CVE-2021-31411 Insecure temporary directory usage in frontend build functionality of Vaadin 14 and 15-19
- CVE-2021-31408 Server session is not invalidated when logout() helper method of Authentication module is used in Vaadin 18-19
- CVE-2019-25027 Reflected cross-site scripting in default RouteNotFoundError view in Vaadin 10 and 11-13
Sources
Also known as GHSA-49r2-73m6-pp8f.