Resource Exhaustion Affecting python-waitress package, versions *


Severity

Recommended
low

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.08% (36th percentile)

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  • Snyk IDSNYK-RHEL8-PYTHONWAITRESS-4403058
  • published26 Mar 2023
  • disclosed3 Feb 2020

Introduced: 3 Feb 2020

CVE-2020-5236  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:8 python-waitress.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python-waitress package and not the python-waitress package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

Waitress version 1.4.2 allows a DOS attack When waitress receives a header that contains invalid characters. When a header like "Bad-header: xxxxxxxxxxxxxxx\x10" is received, it will cause the regular expression engine to catastrophically backtrack causing the process to use 100% CPU time and blocking any other interactions. This allows an attacker to send a single request with an invalid header and take the service offline. This issue was introduced in version 1.4.2 when the regular expression was updated to attempt to match the behaviour required by errata associated with RFC7230. The regular expression that is used to validate incoming headers has been updated in version 1.4.3, it is recommended that people upgrade to the new version of Waitress as soon as possible.

CVSS Scores

version 3.1