National Vulnerability Database

National Vulnerability Database

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CVE-2020-5236 Detail

Current 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.


View Analysis Description

Severity

 


CVSS 3.x Severity and Metrics:

NIST CVSS score
NIST: NVD
Base Score:  6.5 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
Base Score:  5.7 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

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Hyperlink Resource
https://github.com/Pylons/waitress/commit/6e46f9e3f014d64dd7d1e258eaf626e39870ee1f Patch  Third Party Advisory 
https://github.com/Pylons/waitress/security/advisories/GHSA-73m2-3pwg-5fgc Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-400 Uncontrolled Resource Consumption cwe source acceptance level NIST   Reference acceptance level GitHub, Inc.  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

2 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2020-5236
NVD Published Date:
02/03/2020
NVD Last Modified:
02/06/2020
Source:
MITRE