CVE-2021-40491 Server-side request forgery in n/a
The FTP client fails to validate PASV response addresses, allowing attackers to redirect connections to arbitrary hosts, potentially exposing internal services or data.
- 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-2021-40491?
CVE-2021-40491 is a medium-severity server-side request forgery vulnerability in Debian Debian Linux, published on 3 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
The ftp client in GNU Inetutils before 2.2 does not validate addresses returned by PASV/LSPV responses to make sure they match the server address. This is similar to CVE-2020-8284 for curl.
Weakness: CWE-345
Which versions are affected by CVE-2021-40491?
It affects 2 products.
Products include Debian Debian Linux, Gnu Inetutils.
How do I fix CVE-2021-40491?
Upgrade to a fixed version.
Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.
Is CVE-2021-40491 being exploited?
There is no known exploitation of CVE-2021-40491 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as DEBIAN-CVE-2021-40491, GHSA-qw8r-vcwc-vjc9, UBUNTU-CVE-2021-40491, USN-5177-1.