{"id":"PYSEC-2019-66","details":"Waitress through version 1.3.1 implemented a \"MAY\" part of the RFC7230 which states: \"Although the line terminator for the start-line and header fields is the sequence CRLF, a recipient MAY recognize a single LF as a line terminator and ignore any preceding CR.\" Unfortunately if a front-end server does not parse header fields with an LF the same way as it does those with a CRLF it can lead to the front-end and the back-end server parsing the same HTTP message in two different ways. This can lead to a potential for HTTP request smuggling/splitting whereby Waitress may see two requests while the front-end server only sees a single HTTP message. This issue is fixed in Waitress 1.4.0.","modified":"2023-03-14T07:01:09.372726Z","published":"2019-12-20T23:15:00Z","withdrawn":"2023-03-14T07:01:09.372726Z","references":[{"type":"WEB","url":"https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57p"},{"type":"WEB","url":"https://github.com/Pylons/waitress/commit/8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba"},{"type":"WEB","url":"https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2020:0720"}],"affected":[{"package":{"name":"waitress","ecosystem":"PyPI","purl":"pkg:pypi/waitress"},"ranges":[{"type":"GIT","repo":"https://github.com/Pylons/waitress","events":[{"introduced":"0"},{"fixed":"8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba"}]},{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.0"}]}],"versions":["0.1","0.2","0.3","0.4","0.5","0.6","0.6.1","0.7","0.8","0.8.1","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9","0.8.10","0.8.11b0","0.9.0b0","0.9.0b1","0.9.0","1.0a1","1.0a2","1.0.0","1.0.1","1.0.2","1.1.0","1.2.0b1","1.2.0b2","1.2.0b3","1.2.0","1.2.1","1.3.0b0","1.3.0","1.3.1"],"database_specific":{"source":"https://github.com/pypa/advisory-database/blob/main/vulns/waitress/PYSEC-2019-66.yaml"}}],"schema_version":"1.7.3"}