Denial of Service (DoS) Affecting knot_resolver package, versions [,5.3.2)


Severity

Recommended
0.0
high
0
10

CVSS assessment made by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.22% (61st percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UNMANAGED-KNOTRESOLVER-2368780
  • published26 Jan 2022
  • disclosed25 Aug 2021
  • creditUnknown

Introduced: 25 Aug 2021

CVE-2021-40083  (opens in a new tab)
CWE-617  (opens in a new tab)

How to fix?

Upgrade knot_resolver to version 5.3.2 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS). 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).

Details

Denial of Service (DoS) describes a family of attacks, all aimed at making a system inaccessible to its intended and legitimate users.

Unlike other vulnerabilities, DoS attacks usually do not aim at breaching security. Rather, they are focused on making websites and services unavailable to genuine users resulting in downtime.

One popular Denial of Service vulnerability is DDoS (a Distributed Denial of Service), an attack that attempts to clog network pipes to the system by generating a large volume of traffic from many machines.

When it comes to open source libraries, DoS vulnerabilities allow attackers to trigger such a crash or crippling of the service by using a flaw either in the application code or from the use of open source libraries.

Two common types of DoS vulnerabilities:

  • High CPU/Memory Consumption- An attacker sending crafted requests that could cause the system to take a disproportionate amount of time to process. For example, commons-fileupload:commons-fileupload.

  • Crash - An attacker sending crafted requests that could cause the system to crash. For Example, npm ws package

References

CVSS Scores

version 3.1