# CVE-2024-49768: Waitress has request processing race condition in HTTP pipelining with invalid first request

Source: https://junglewise.ai/threats/cve-2024-49768-waitress-has-request-processing-race-condition-in-http-pipelining  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2024-10-29  
License: CC BY 4.0 with a link back

CVE-2024-49768 · Severity: low · CVSS 3.1 · Published 2024-10-29

Waitress is a Web Server Gateway Interface server for Python 2 and 3. A remote client may send a request that is exactly recv_bytes (defaults to 8192) long, followed by a secondary request using HTTP pipelining. When request lookahead is disabled (default) we won't read any more requests, and when the first request fails due to a parsing error, we simply close the connection. However when request lookahead is enabled, it is possible to process and receive the first request, start sending the error message back to the client while we read the next request and queue it. This will allow the secondary request to be serviced by the worker thread while the connection should be closed. Waitress 3.0.1 fixes the race condition. As a workaround, disable channel_request_lookahead, this is set to 0 by default disabling this feature.

Technologies: [waitress (PyPI)](https://junglewise.ai/threats/technologies/waitress). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2024-49768 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2024-49768 being exploited in the wild.

**How severe is CVE-2024-49768?** Low severity, with a CVSS score of 3.1, published 29 October 2024.

**Which products and versions are affected?** waitress (PyPI) ECOSYSTEM:introduced=2.0.0,fixed=3.0.1, GIT:introduced=0,fixed=e4359018537af376cf24bd13616d861e2fb76f65|ECOSYSTEM:introduced=2.0.0,fixed=3.0.1.

**Is there a fix for CVE-2024-49768?** 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.

**Am I affected by CVE-2024-49768?** 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

  ```sh
  pip install "waitress>=3.0.1"
  ```


## Affected products

- waitress (PyPI) ECOSYSTEM:introduced=2.0.0,fixed=3.0.1, GIT:introduced=0,fixed=e4359018537af376cf24bd13616d861e2fb76f65|ECOSYSTEM:introduced=2.0.0,fixed=3.0.1

## Identifiers

- CVE-2024-49768
- GHSA-9298-4cf8-g4wj
- PYSEC-2024-210

## Related threats

- [Waitress denial of service via unclean socket handling](https://junglewise.ai/threats/cve-2024-49769-waitress-denial-of-service-via-unclean-socket-handling)
- [Uncaught Exception (due to a data race) leads to process termination in Waitress](https://junglewise.ai/threats/cve-2022-31015-uncaught-exception-due-to-a-data-race-leads-to-process)
- [HTTP Request Smuggling in waitress](https://junglewise.ai/threats/cve-2022-24761-http-request-smuggling-in-waitress)
- [Catastrophic backtracking in regex allows Denial of Service in Waitress](https://junglewise.ai/threats/cve-2020-5236-catastrophic-backtracking-in-regex-allows-denial-of-service-in)
- [Duplicate Advisory: Inconsistent Interpretation of HTTP Requests in Waitress](https://junglewise.ai/threats/cve-2019-16792-http-request-smuggling-content-length-sent-twice-in-waitress)