Denial of Service (DoS) Affecting oauthlib package, versions [3.1.1,3.2.2)


Severity

Recommended
0.0
medium
0
10

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

Threat Intelligence

EPSS
0.36% (72nd percentile)

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  • Snyk IDSNYK-PYTHON-OAUTHLIB-3021142
  • published11 Sept 2022
  • disclosed11 Sept 2022
  • creditSebastian Chnelik (SCH227)

Introduced: 11 Sep 2022

CVE-2022-36087  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade oauthlib to version 3.2.2 or higher.

Overview

Affected versions of this package are vulnerable to Denial of Service (DoS) when an attacker provides a malicious redirect URI. An attacker can also leverage the usage of the uri_validate functions depending on where it is used.

Note: Users are affected by this issue ONLY when OAuthLib applications are using OAuth2.0 provider support or when using directly the uri_validate function.

PoC

is_absolute_uri("http://[:::::::::::::::::::::::::::::::::::::::]/path")

Workaround

Users that are not able to upgrade to the fixed version should verify the redirect_uri in a web toolkit before oauthlib is called. This is to check if : is present and if so, to reject the request, assuming no port or IPv6 is fundamentally required.

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