CVE-2019-16786

Description

Waitress through version 1.3.1 would parse the Transfer-Encoding header and only look for a single string value, if that value was not chunked it would fall through and use the Content-Length header instead. According to the HTTP standard Transfer-Encoding should be a comma separated list, with the inner-most encoding first, followed by any further transfer codings, ending with chunked. Requests sent with: "Transfer-Encoding: gzip, chunked" would incorrectly get ignored, and the request would use a Content-Length header instead to determine the body size of the HTTP message. This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining. This issue is fixed in Waitress 1.4.0.

Weakness classification

• CWE-444: Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Primary references

• security-advisories@github.com — Third Party Advisory
• security-advisories@github.com — Release Notes, Vendor Advisory
• security-advisories@github.com — Patch, Third Party Advisory
• security-advisories@github.com — Third Party Advisory
• security-advisories@github.com — Mailing List, Third Party Advisory
• security-advisories@github.com
• security-advisories@github.com
• security-advisories@github.com — Patch, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Release Notes, Vendor Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory
• af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory