Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Agendaless | Waitress | 1.4.2 |
Related Weaknesses (CWE)
References
- https://github.com/Pylons/waitress/commit/6e46f9e3f014d64dd7d1e258eaf626e39870eePatchThird Party Advisory
- https://github.com/Pylons/waitress/security/advisories/GHSA-73m2-3pwg-5fgcThird Party Advisory
- https://github.com/Pylons/waitress/commit/6e46f9e3f014d64dd7d1e258eaf626e39870eePatchThird Party Advisory
- https://github.com/Pylons/waitress/security/advisories/GHSA-73m2-3pwg-5fgcThird Party Advisory
FAQ
What is CVE-2020-5236?
CVE-2020-5236 is a vulnerability with a CVSS score of 5.7 (MEDIUM). 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...
How severe is CVE-2020-5236?
CVE-2020-5236 has been rated MEDIUM with a CVSS base score of 5.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-5236?
Check the references section above for vendor advisories and patch information. Affected products include: Agendaless Waitress.