CVE-2021-40083
Knot Resolver DNS Denial of Service
Description
Knot Resolver before 5.3.2 is prone to an assertion failure, triggerable by a remote attacker in an edge case (NSEC3 with too many iterations used for a positive wildcard proof).
INFO
Published Date :
Aug. 25, 2021, 1:15 a.m.
Last Modified :
Aug. 30, 2021, 7:29 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
3.6
Exploitability Score :
3.9
Public PoC/Exploit Available at Github
CVE-2021-40083 has a 1 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2021-40083.
| URL | Resource |
|---|---|
| https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/1169 | Patch Third Party Advisory |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Imoro Umar Farouq's report on Internal Network Penetration Testing
Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-40083 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-40083 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
Initial Analysis by [email protected]
Aug. 30, 2021
Action Type Old Value New Value Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:N/A:P) Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/1169 No Types Assigned https://gitlab.nic.cz/knot/knot-resolver/-/merge_requests/1169 Patch, Third Party Advisory Added CWE NIST CWE-617 Added CPE Configuration OR *cpe:2.3:a:nic:knot_resolver:*:*:*:*:*:*:*:* versions up to (excluding) 5.3.2
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-40083 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-40083
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
0.22 }} 0.03%
score
0.59543
percentile