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Denial of Service (DoS) Affecting nokogiri package, versions <1.11.4

0.0
high

Snyk CVSS

    Attack Complexity Low
    Availability High

    Threat Intelligence

    Exploit Maturity Proof of concept
    EPSS 0.87% (83rd percentile)
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NVD
7.5 high
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SUSE
3.1 low
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Red Hat
7.5 high

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  • Snyk ID SNYK-RUBY-NOKOGIRI-1293239
  • published 18 May 2021
  • disclosed 17 May 2021
  • credit Unknown
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Introduced: 17 May 2021

CVE-2019-20388 Open this link in a new tab
CWE-400 Open this link in a new tab

How to fix?

Upgrade nokogiri to version 1.11.4 or higher.

Overview

nokogiri is a gem for parsing HTML, XML, SAX, and Reader.

Affected versions of this package are vulnerable to Denial of Service (DoS). Vulnerable version of libxml2 was used.

The fix to this updates the vendored libxml2 from v2.9.10 to v2.9.12 which addresses:

  • CVE-2019-20388
  • CVE-2020-24977
  • CVE-2021-3517
  • CVE-2021-3518
  • CVE-2021-3537
  • CVE-2021-3541

Please note that this advisory only applies to the CRuby implementation of Nokogiri < 1.11.4, and only if the packaged version of libxml2 is being used. If you've overridden defaults at installation time to use system libraries instead of packaged libraries, you should instead pay attention to your distro's libxml2 release announcements.

NOTE: This vulnerability has also been identified as: CVE-2021-3537, CVE-2021-3541, CVE-2020-24977, CVE-2021-3517, CVE-2021-3518

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