Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
Low
Attack Vector
Network
0

CVE-2020-5236

Disclosure Date: February 04, 2020
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

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.

Add Assessment

No one has assessed this topic. Be the first to add your voice to the community.

CVSS V3 Severity and Metrics
Base Score:
6.5 Medium
Impact Score:
3.6
Exploitability Score:
2.8
Vector:
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector (AV):
Network
Attack Complexity (AC):
Low
Privileges Required (PR):
Low
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
None
Availability (A):
High

General Information

Vendors

  • agendaless

Products

  • waitress 1.4.2

Additional Info

Technical Analysis