CVE-2021-40524 Denial of service in n/a
Attackers can upload unbounded files due to a quota mechanism flaw, causing server hangs or denial of service in Pure-FTPd.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-40524?
CVE-2021-40524 is a high-severity denial of service vulnerability in n/a, published on 5 Sep 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In Pure-FTPd before 1.0.50, an incorrect max_filesize quota mechanism in the server allows attackers to upload files of unbounded size, which may lead to denial of service or a server hang. This occurs because a certain greater-than-zero test does not anticipate an initial -1 value. (Versions 1.0.23 through 1.0.49 are affected.)
Weakness: CWE-434
Which versions are affected by CVE-2021-40524?
It affects 1 product.
Products include Pureftpd Pure-Ftpd.
How do I fix CVE-2021-40524?
Upgrade to a fixed version.
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-2021-40524 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-40524 exists.
Public exploit code: 1 Nuclei template.
Other vulnerabilities in n/a
Sources
Also known as DEBIAN-CVE-2021-40524, DLA-4360-1, GHSA-p53v-96v3-p5jg, UBUNTU-CVE-2021-40524.