CVE-2021-3331 Command injection in n/a

Critical 9.8 Published 27 Jan 2021 Updated 8 Oct 2026

Remote attackers can execute arbitrary programs via crafted URLs in WinSCP, affecting default installations handling sftp links.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-3331?

CVE-2021-3331 is a critical command injection vulnerability in n/a, published on 27 Jan 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

WinSCP before 5.17.10 allows remote attackers to execute arbitrary programs when the URL handler encounters a crafted URL that loads session settings. (For example, this is exploitable in a default installation in which WinSCP is the handler for sftp:// URLs.)

Which versions are affected by CVE-2021-3331?

It affects 1 product.

Products include Winscp Winscp.

How do I fix CVE-2021-3331?

No fix has been published for CVE-2021-3331 yet. Limit exposure of the affected software until one is available.

Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.

Is CVE-2021-3331 being exploited?

There is no known exploitation of CVE-2021-3331 in the wild and no public exploit code.

Sources

Also known as GHSA-rx6x-hw9j-xhm3.