CVE-2019-16785

Aliases:GHSA-pg36-wpm5-g57pPYSEC-2019-136
Advisory lineage Upstream: 0 Downstream: 12
Modified
Published: 20 Dec 2019, 23:00
Last modified:05 Aug 2024, 01:24

Vulnerability Summary

Overall Risk (default)
medium
40/100
CVSS Score
7.5 HIGH
v3.1 (nvd)
EPSS Score
1.02% LOW
1% probability 0.00%
KEV
Not listed
Ransomware
No reports
Public exploits
1 found
Dark Web
Not detected

Timeline

20 Dec 2019, 23:00
Published
Vulnerability first disclosed
05 Aug 2024, 01:24
Last Modified
Vulnerability information updated

Description

Waitress through version 1.3.1 implemented a "MAY" part of the RFC7230 which states: "Although the line terminator for the start-line and header fields is the sequence CRLF, a recipient MAY recognize a single LF as a line terminator and ignore any preceding CR." Unfortunately if a front-end server does not parse header fields with an LF the same way as it does those with a CRLF it can lead to the front-end and the back-end server parsing the same HTTP message in two different ways. This can lead to a potential for HTTP request smuggling/splitting whereby Waitress may see two requests while the front-end server only sees a single HTTP message. This issue is fixed in Waitress 1.4.0.

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:H/SI:L/SA:N
  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N
  • v3.1•HIGH•Score: 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
  • v2.0•MEDIUM•Score: 5AV:N/AC:L/Au:N/C:N/I:P/A:N

EPSS Trends

Current EPSS score: 1.02%• Percentile: 78%

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

    ≤ 1.3.1

  • debian•debian_linux

    9.0

  • fedoraproject•fedora

    30 | 31

  • oracle•communications_cloud_native_core_network_function_cloud_native_environment

    1.10.0

  • pylons•waitress

    ≥ <= 1.3.1, ≤ 1.3.1

  • PyPI•waitress

    < 8eba394ad75deaf9e5cd15b78a3d16b12e6b0eba | < 1.4.0

  • redhat•openstack

    15

References (15)