Denial of Service (DoS) Affecting unbound package, versions [,1.16.2)


Severity

Recommended
0.0
high
0
10

CVSS assessment by Snyk's Security Team. Learn more

Threat Intelligence

EPSS
0.09% (27th percentile)

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  • Snyk IDSNYK-UNMANAGED-UNBOUND-2964955
  • published2 Aug 2022
  • disclosed2 Aug 2022
  • creditXiang Li from the Network and Information Security Lab of Tsinghua University

Introduced: 2 Aug 2022

CVE-2022-30698  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade unbound to version 1.16.2 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) by targeting an Unbound instance. Unbound is queried for a subdomain of a rogue domain name. The rogue nameserver returns delegation information for the subdomain that updates Unbound's delegation cache. This action can be repeated before the expiry of the delegation information by querying Unbound for a second-level subdomain in which the rogue nameserver provides new delegation information. Since Unbound is a child-centric resolver, the ever-updating child delegation information can keep a rogue domain name resolvable long after revocation.

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

CVSS Base Scores

version 3.1