CVE-2020-5236: Catastrophic backtracking in regex allows Denial of Service in Waitress
Pylons · Waitress
Affected: Pylons Waitress · Exploitation: possible (1 to 10%)
Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.
Higher than 84% of scored CVEs
DescriptionCVE.org
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.
Affected products1
From the CVE record. A product or version that is not listed is unknown, not unaffected.
- Pylons · Waitress= 1.4.2
On the Atlas
Every published CVE is on the CyberSIXT Atlas, grouped by weakness, vendor and month.
- Exploitation
- Possible (1 to 10%). EPSS between 1% and 10%.
- CISA KEV
- Not listed
- Public check
- No public nuclei template
- Vendor
- Pylons
- Published
- February 2020
CoverageNo articles yet
No CyberSIXT article names CVE-2020-5236 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.