CVE-2019-16785
waitress - security update
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.
How to fix CVE-2019-16785
To remediate CVE-2019-16785, upgrade the affected package to a fixed version below.
- —upgrade to 1.4.1-1 or later
- —upgrade to 1.0.1-1+deb9u1 or later
- —upgrade to 1.4.0 or later
- —upgrade to 8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba or later
Is CVE-2019-16785 being exploited?
Low — EPSS is 0.8%, meaning exploitation activity has not been observed at scale.
Affected packages (4)
- from 0, < 1.4.1-1
- from 0, < 1.0.1-1+deb9u1
- from 0, < 1.4.0
- from 0, < 8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba | from 0, < 1.4.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:H/SI:L/SA:N |
| osv | CVSS 3.1 | HIGH7.1 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N |