CVE Vulnerability

CVE-2020-5236

Waitress version 1.4.2 allows a DOS attack When waitress receives a header that contains invalid characters. When a header like "Bad-header: xxxxxxxxxxxxxxxx10" 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.

6.8 /10

CVSS v2.0 :

V3 Legend

Vector :

Exploitability : 8 / Impact : 6.9

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact COMPLETE

Scope

6.5 /10

CVSS v3.0 : MEDIUM

V3 Legend

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

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

Configuration 1

cpe:2.3:a:agendaless:waitress:1.4.2:*:*:*:*:*:*:*
Information

Published : 2020-02-04 03:15

Updated : 2020-02-06 06:46

NVD link : CVE-2020-5236

Mitre link : CVE-2020-5236

Products Affected
No products.
CWE
CWE-400