CVE-2024-49769: Waitress denial of service via unclean socket handling

CVE-2024-49769 · Severity: low · CVSS 3.1 · Published 2024-10-29

Waitress is a Python web application server used to host web services and applications. A remote attacker can cause the server to enter a busy-loop consuming excessive CPU resources by closing connections before the server fully initializes them, leading to potential service degradation or complete unavailability without requiring authentication or special privileges.

Technologies: waitress (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2024-49769 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2024-49769 being exploited in the wild.
How severe is CVE-2024-49769?
Low severity, with a CVSS score of 3.1, published 29 October 2024.
Which products and versions are affected?
waitress (PyPI) ECOSYSTEM:introduced=0,fixed=3.0.1, GIT:introduced=0,fixed=1ae4e894c9f76543bee06584001583fc6fa8c95c|ECOSYSTEM:introduced=0,fixed=3.0.1.
Is there a fix for CVE-2024-49769?
Yes. waitress (PyPI): upgrade to 3.0.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2024-49769 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2024-49769?
Check whether you run waitress (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • waitress (PyPI): upgrade to 3.0.1 or later
    pip install "waitress>=3.0.1"

Technical details

The vulnerability is a resource cleanup failure (CWE-772) caused by a race condition in socket handling. When a remote client closes a connection before waitress calls getpeername(), the server fails to properly clean up the socket descriptor and remove it from the active socket list. The main thread then enters a busy-loop repeatedly attempting to write to the defunct socket without properly removing it, consuming CPU resources in the process. The attack is network-accessible, requires no authentication or user interaction, and can exhaust available sockets on the target system with minimal attacker resources. Waitress 3.0.1 patches the vulnerability by fixing the race condition and properly cleaning up failed connections.

Affected products

  • Pylons Waitress all versions before 3.0.1

Identifiers

  • CVE-2024-49769
  • GHSA-3f84-rpwh-47g6
  • PYSEC-2024-211

Timeline

  • 2024-10-29: disclosed
  • 2024-10-29: patched: Waitress 3.0.1 released with fixes

References

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