CVE-2019-16789

HIGH EPSS 83.3%
Published Dec 26, 20196y ago · Modified Jun 17, 20262w ago
8.2 CVSS 3.1
High
Find Similar
Published Dec 26, 2019 6y ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
8.2
Exploitability
3.9
Impact
4.2
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality Low
Integrity High
Availability None

Threat Intelligence

EPSS Exploit Probability
83.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-444

Affected Products 6

VendorProductVersionRange
agendalesswaitress* ≤1.4.0
oraclecommunications_cloud_native_core_network_function_cloud_native_environment1.10.0any
debiandebian_linux9.0any
fedoraprojectfedora30any
fedoraprojectfedora31any
redhatopenstack15any

References 8

  • access.redhat.com https://access.redhat.com/errata/RHSA-2020:0720
    Third Party Advisory
  • docs.pylonsproject.org https://docs.pylonsproject.org/projects/waitress/en/latest/#security-fixes
    Release NotesVendor Advisory
  • github.com https://github.com/Pylons/waitress/commit/11d9e138125ad46e951027184b13242a3c1de017
    PatchThird Party Advisory
  • github.com https://github.com/github/advisory-review/pull/14604
    Broken LinkThird Party Advisory
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2022/05/msg00011.html
    Mailing ListThird Party Advisory
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GVDHR2DNKCNQ7YQXISJ45NT4IQDX3LJ7/
  • lists.fedoraproject.org https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/LYEOTGWJZVKPRXX2HBNVIYWCX73QYPM5/
  • oracle.com https://www.oracle.com/security-alerts/cpuapr2022.html
    PatchThird Party Advisory

Remediation

  • github.com https://github.com/Pylons/waitress/commit/11d9e138125ad46e951027184b13242a3c1de017
    PatchThird Party Advisory
  • oracle.com https://www.oracle.com/security-alerts/cpuapr2022.html
    PatchThird Party Advisory