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.
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2020-02-04T03:05:14

Updated: 2024-08-04T08:22:09.008Z

Reserved: 2020-01-02T00:00:00

Link: CVE-2020-5236

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2020-02-04T03:15:10.750

Modified: 2020-02-06T18:46:27.267

Link: CVE-2020-5236

cve-icon Redhat

Severity : Moderate

Publid Date: 2020-02-03T00:00:00Z

Links: CVE-2020-5236 - Bugzilla