CVE-2021-27221 Missing authorization in n/a
Authenticated FTP users can overwrite arbitrary configuration files, potentially altering device settings, though the vendor considers this intended behavior.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-27221?
CVE-2021-27221 is a high-severity missing authorization vulnerability in Mikrotik Routeros, published on 19 Mar 2021. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
MikroTik RouterOS 6.47.9 allows remote authenticated ftp users to create or overwrite arbitrary .rsc files via the /export command. NOTE: the vendor's position is that this is intended behavior because of how user policies work
Which versions are affected by CVE-2021-27221?
It affects 1 product.
Products include Mikrotik Routeros.
How do I fix CVE-2021-27221?
No fix has been published for CVE-2021-27221 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2021-27221 being exploited?
There is no known exploitation of CVE-2021-27221 in the wild and no public exploit code.
Other vulnerabilities in Mikrotik Routeros
- CVE-2018-7445 MikroTik RouterOS Stack-Based Buffer Overflow
- CVE-2026-86060 MikroTik RouterOS Improper Neutralization of Argument Delimiters in a Command
- CVE-2018-14847 MikroTik Router OS Directory Traversal
- CVE-2026-67277 MikroTik RouterOS Missing Authentication for Critical Function
- CVE-2026-67279 Mikrotik RouterOS Improper Enforcement of Behavioral Workflow
Sources
Also known as GHSA-xf77-xqpr-2gh9.