CVE-2021-41380 Denial of service in n/a
A remote VNC server can cause RealVNC Viewer to hang via crafted protocol data, requiring user interaction to connect to a malicious server.
- 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-2021-41380?
CVE-2021-41380 is a medium-severity denial of service vulnerability in n/a, published on 17 Sep 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
RealVNC Viewer 6.21.406 allows remote VNC servers to cause a denial of service (application crash) via crafted RFB protocol data. NOTE: It is asserted that this issue requires social engineering a user into connecting to a fake VNC Server. The VNC Viewer application they are using will then hang, until terminated, but no memory leak occurs - the resources are freed once the hung process is terminated and the resource usage is constant during the hang. Only the process that is connected to the fake Server is affected. This is an application bug, not a security issue
Weakness: CWE-20
Which versions are affected by CVE-2021-41380?
It affects 1 product.
Products include Realvnc Vnc Viewer.
How do I fix CVE-2021-41380?
No fix has been published for CVE-2021-41380 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-41380 being exploited?
There is no known exploitation of CVE-2021-41380 in the wild and no public exploit code.
Sources
Also known as GHSA-789c-r6w2-66gw.