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CVE-2019-16785

HTTP Request Smuggling: LF vs CRLF handling in Waitress PUBLISHED

Description (CNA)

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.

Affected (CNA)

Vendor / productVersions
Pylons / Waitressaffected <= 1.3.1 through 1.3.1

CWE

CWE-444

References

ADP enrichment

CVE

No English description supplied.