CVE-2020-5236

Published Feb 4, 2020

Last updated 3 months ago

Overview

Description
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.
Source
security-advisories@github.com
NVD status
Modified

Risk scores

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
3.6
Exploitability score
2.8
Vector string
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

CVSS 2.0

Type
Primary
Base score
6.8
Impact score
6.9
Exploitability score
8
Vector string
AV:N/AC:L/Au:S/C:N/I:N/A:C

Weaknesses

security-advisories@github.com
CWE-400
nvd@nist.gov
CWE-400

Social media

Hype score
Not currently trending

Configurations