CVE-2019-16786
CVE-2019-16786 — HTTP Request Smuggling: Invalid Transfer-Encoding in Waitress
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.
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
2%
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/Pylons/waitress/security/advisories/GHSA-g2xc-35jw-c63p
x_refsource_CONFIRM
- github.com/Pylons/waitress/commit/f11093a6b3240fc26830b6111e826128af7771c3
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.