CVE-2021-25218 Denial of service in BIND9
Remote attackers can cause a denial of service in BIND DNS servers by triggering an assertion failure when RRL is enabled and UDP fragmentation is required.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-25218?
CVE-2021-25218 is a high-severity denial of service vulnerability in Fedoraproject Fedora, published on 18 Aug 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In BIND 9.16.19, 9.17.16. Also, version 9.16.19-S1 of BIND Supported Preview Edition When a vulnerable version of named receives a query under the circumstances described above, the named process will terminate due to a failed assertion check. The vulnerability affects only BIND 9 releases 9.16.19, 9.17.16, and release 9.16.19-S1 of the BIND Supported Preview Edition.
Weakness: CWE-617
Which versions are affected by CVE-2021-25218?
It affects 2 products.
Products include Fedoraproject Fedora, Isc Bind.
How do I fix CVE-2021-25218?
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-2021-25218 being exploited?
There is no known exploitation of CVE-2021-25218 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as ALPINE-CVE-2021-25218, GHSA-cc8x-chx9-c63q.