CVE-2019-16789
CVE-2019-16789 — HTTP Request Smuggling in Waitress: Invalid whitespace characters in headers
In Waitress through version 1.4.0, if a proxy server is used in front of waitress, an invalid request may be sent by an attacker that bypasses the front-end and is parsed differently by waitress leading to a potential for HTTP request smuggling. Specially crafted requests containing special whitespace characters in the Transfer-Encoding header would get parsed by Waitress as being a chunked request, but a front-end server would use the Content-Length instead as the Transfer-Encoding header is considered invalid due to containing invalid characters. If a front-end server does HTTP pipelining to a backend Waitress server this could lead to HTTP request splitting which may lead to potential cache poisoning or unexpected information disclosure. This issue is fixed in Waitress 1.4.1 through more strict HTTP field validation.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
3%
chance of exploitation in 30 days
CVSS base
7.1
HIGH
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.1 | CVSS 3.1 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-444
References
8 on the record
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
vendor-advisory, x_refsource_FEDORA
- lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/
vendor-advisory, x_refsource_FEDORA
- access.redhat.com/errata/RHSA-2020:0720
vendor-advisory, x_refsource_REDHAT
- www.oracle.com/security-alerts/cpuapr2022.html
x_refsource_MISC
- docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
x_refsource_MISC
- github.com/github/advisory-review/pull/14604
x_refsource_CONFIRM
- github.com/Pylons/waitress/commit/11d9e138125ad46e951027184b13242a3c1de017
x_refsource_MISC
- lists.debian.org/debian-lts-announce/2022/05/msg00011.html
mailing-list, x_refsource_MLIST
Elsewhere on this site
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.