CVE-2019-16789

Aliases:GHSA-968f-66r5-5v74PYSEC-2019-138
Advisory lineage Upstream: 0 Downstream: 13
Modified
Published: 26 Dec 2019, 16:40
Last modified:05 Aug 2024, 01:24

Vulnerability Summary

Overall Risk (default)
medium
33/100
CVSS Score
8.2 HIGH
v3.1 (nvd)
EPSS Score
0.88% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

26 Dec 2019, 16:40
Published
Vulnerability first disclosed
05 Aug 2024, 01:24
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v4.0•MEDIUM•Score: 5.1CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N
  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N
  • v3.1•HIGH•Score: 8.2CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
  • v2.0•MEDIUM•Score: 6.4AV:N/AC:L/Au:N/C:P/I:P/A:N

EPSS Trends

Current EPSS score: 0.88%• Percentile: 76%

Techniques & Countermeasures

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

    The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.

Affected Systems

  • agendaless•waitress

    ≤ 1.4.0

  • debian•debian_linux

    9.0

  • fedoraproject•fedora

    30 | 31

  • oracle•communications_cloud_native_core_network_function_cloud_native_environment

    1.10.0

  • pylons•waitress

    ≥ < 1.4.1, < 1.4.1

  • PyPI•waitress

    < 1.4.2 | < 11d9e138125ad46e951027184b13242a3c1de017 | < 1.4.1

  • redhat•openstack

    15

References (18)