PyPI: pheonix-waitress
CVE-2019-16785
Safety vulnerability ID: SFTY-20191220-27176
Safety legacy ID: pyup.io-49025
Pheonix-waitress 1.4.0 includes a fix for CVE-2019-16785: 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. https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57p
Overview
HTTP Request Smuggling: LF vs CRLF handling in Waitress
Advisory
Pheonix-waitress 1.4.0 includes a fix for CVE-2019-16785: 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. https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57p
How to Fix
Mitigation and Workarounds
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Vulnerable Functions
Functions linked to known vulnerabilities.
References
- https://getsafety.com/vulnerabilities/SFTY-20191220-27176/CVE-2019-16785
- https://github.com/Pylons/waitress/security/advisories/GHSA-pg36-wpm5-g57p
- https://nvd.nist.gov/vuln/detail/CVE-2019-16785
- 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
- https://www.oracle.com/security-alerts/cpuapr2022.html
- https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html
- https://github.com/pypa/advisory-database/tree/main/vulns/waitress/PYSEC-2019-136.yaml
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5
- https://github.com/advisories/GHSA-pg36-wpm5-g57p
Verified by Safety
Our Cybersecurity Intelligence Team reviewed this vulnerability. We combine public data with our own research to find issues not yet reported to public sources.
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