HTTP Request Smuggling in Waitress: Invalid whitespace characters in headers (Follow-up)

CVE-2019-16789 → View on GitHub ↗ View on CVE.org ↗ View on NVD ↗

Description

Impact

The patches introduced to fix https://github.com/Pylons/waitress/security/advisories/GHSA-m5ff-3wj3-8ph4 were not complete and still would allow an attacker to smuggle requests/split a HTTP request with invalid data.

This updates the existing CVE with ID: CVE-2019-16789

Patches

Waitress version 1.4.2 has been updated to now validate HTTP headers better to avoid the issue, completely fixing all known issues with whitespace.

Workarounds

There are no work-arounds, upgrading to Waitress 1.4.2 is highly recommended.

References

See https://github.com/Pylons/waitress/security/advisories/GHSA-m5ff-3wj3-8ph4 for more information on the security issue.

For more information

If you have any questions or comments about this advisory:

  • open an issue at https://github.com/Pylons/waitress/issues (if not sensitive or security related)
  • email the Pylons Security mailing list: [email protected] (if security related)

Basic information

Type
reviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Open repository advisory ↗
Source code
Browse source ↗
Published (advisory)
2020-01-06 18:44:21 UTC
Updated
2024-11-19 13:58:28 UTC
GitHub reviewed
2020-01-06 18:43:11 UTC
NVD published
2019-12-26

EPSS Score

Score Percentile
0.88% 74.94%

CVSS Scores

Base score Version Severity Vector
7.1 3.1 —
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
5.1 4.0 —
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:H/SA:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network.
Attack complexity (AC:L)
Exploitation conditions are straightforward and stable.
Attack requirements (AT:P)
Additional preconditions must be present for exploitation.
Privileges required (PR:L)
Low privileges are required.
User interaction (UI:N)
No user interaction is required.
Vulnerable system confidentiality impact (VC:N)
No confidentiality impact on the vulnerable system.
Vulnerable system integrity impact (VI:N)
No integrity impact on the vulnerable system.
Vulnerable system availability impact (VA:N)
No availability impact on the vulnerable system.
Subsequent system confidentiality impact (SC:L)
Limited confidentiality impact on subsequent systems.
Subsequent system integrity impact (SI:H)
High integrity impact on subsequent systems.
Subsequent system availability impact (SA:N)
No availability impact on subsequent systems.

Identifiers

Type Value
GHSA GHSA-968f-66r5-5v74 ↗
CVE CVE-2019-16789 ↗

CWEs

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

Affected packages (1)

Vulnerable version ranges and first patched releases as published by GitHub.

Ecosystem Package Vulnerable range First patched Vulnerable functions
pip waitress < 1.4.2 1.4.2 —

References

cvelogic Threat Intelligence