SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-16786

This could allow for Waitress to treat a single request as multiple requests in the case of HTTP pipelining.

HIGH 7.5EPSS 2.38%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.38%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS
2.38% probability · 83th percentile
CISA KEV
Not listed
Weakness
CWE-444
Affected
agendaless/waitress · oracle/communications cloud native core network function cloud native environment · debian/debian linux · fedoraproject/fedora · redhat/openstack
Source
security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.