CVE-2017-15271 Use after free in n/a
Remote attackers can cause a denial of service in PSFTPd by triggering a use-after-free via crafted SSH strings before authentication.
- 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-2017-15271?
CVE-2017-15271 is a medium-severity use after free vulnerability in n/a, published on 15 Nov 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A use-after-free issue could be triggered remotely in the SFTP component of PSFTPd 10.0.4 Build 729. This issue could be triggered prior to authentication. The PSFTPd server did not automatically restart, which enabled attackers to perform a very effective DoS attack against this service. By sending a crafted SSH identification / version string to the server, a NULL pointer dereference could be caused, apparently because of a race condition in the window message handling, performing the cleanup for invalid connections. This incorrect cleanup code has a use-after-free.
Weakness: CWE-416
Which versions are affected by CVE-2017-15271?
It affects 1 product.
Products include Psftp Psftpd.
How do I fix CVE-2017-15271?
No fix has been published for CVE-2017-15271 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2017-15271 being exploited?
There is no known exploitation of CVE-2017-15271 in the wild and no public exploit code.
Public exploit code: 1 Exploit-DB entry.
Other vulnerabilities in n/a
Sources
Also known as GHSA-fcg6-9hqq-q764.