http://bugzilla.opensuse.org/show_bug.cgi?id=1162656 Bug ID: 1162656 Summary: VUL-1: CVE-2020-5236: python-waitress: DOS attack whena header that contains invalid characters is received Classification: openSUSE Product: openSUSE Distribution Version: Leap 42.3 Hardware: Other URL: https://smash.suse.de/issue/252361/ OS: Other Status: NEW Severity: Normal Priority: P5 - None Component: Security Assignee: dmueller@suse.com Reporter: atoptsoglou@suse.com QA Contact: security-team@suse.de Found By: Security Response Team Blocker: --- 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: 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. References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2020-5236 https://github.com/Pylons/waitress/security/advisories/GHSA-73m2-3pwg-5fgc https://github.com/Pylons/waitress/commit/6e46f9e3f014d64dd7d1e258eaf626e398... http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-5236 -- You are receiving this mail because: You are on the CC list for the bug.