CVE-2019-16785

Description

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.

References

https://www.oracle.com/security-alerts/cpuapr2022.html

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/

https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html

https://github.com/Pylons/waitress/commit/8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba

https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes

https://access.redhat.com/errata/RHSA-2020:0720

Details

Source: Mitre, NVD

Risk Information

CVSS v2

CVSS v3