Denial of Service (DoS) Affecting channels package, versions [3.0.0, 3.0.3)


Severity

Recommended
0.0
high
0
10

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

Threat Intelligence

EPSS
0.8% (72nd percentile)

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  • Snyk IDSNYK-PYTHON-CHANNELS-1078280
  • published22 Feb 2021
  • disclosed22 Feb 2021
  • creditUnknown

Introduced: 22 Feb 2021

CVE-2020-35681  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade channels to version 3.0.3 or higher.

Overview

channels is a Developer-friendly asynchrony for Django.

Affected versions of this package are vulnerable to Denial of Service (DoS). It allows remote attackers to obtain sensitive information from a different request scope. The legacy channels.http.AsgiHandler class, used for handling HTTP type requests in an ASGI environment prior to Django 3.0, did not correctly separate request scopes in Channels 3.0. In many cases this would result in a crash but with correct timing responses could be sent to the wrong client, resulting in potential leakage of session identifiers and other sensitive data. Note that this affects only the legacy Channels provided class, and not Django's similar ASGIHandler, available from Django 3.0.

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 Base Scores

version 3.1