HTTP Request Smuggling Affecting py3-waitress package, versions <1.4.0-r0


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.77% (82nd percentile)

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  • Snyk IDSNYK-ALPINE320-PY3WAITRESS-7013918
  • published23 May 2024
  • disclosed20 Dec 2019

Introduced: 20 Dec 2019

CVE-2019-16785  (opens in a new tab)
CWE-444  (opens in a new tab)

How to fix?

Upgrade Alpine:3.20 py3-waitress to version 1.4.0-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream py3-waitress package and not the py3-waitress package as distributed by Alpine. See How to fix? for Alpine:3.20 relevant fixed versions and status.

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.

CVSS Scores

version 3.1