critical
9.1
CWE
367 444 362
Advisory Published
Advisory Published
Updated

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

First published: Tue Oct 29 2024(Updated: )

### Impact 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. ### Patches Waitress 3.0.1 fixes the race condition. ### Workarounds Disable `channel_request_lookahead`, this is set to `0` by default disabling this feature. For this vulnerability this value is required to be changed from the default. ### For more information If you have any questions or comments about this advisory: * Open an issue in https://github.com/Pylons/waitress/issues (if not sensitive or security related) * email the Pylons Security mailing list: [pylons-project-security@googlegroups.com](mailto:pylons-project-security@googlegroups.com) (if security related) ### Thanks - m4yfly and urn1ce From TianGong Team of Legendsec at Qi'anxin Group.

Credit: security-advisories@github.com security-advisories@github.com

Affected SoftwareAffected VersionHow to fix
debian/waitress<=2.1.2-2
1.4.4-1.1+deb11u1
1.4.4-1.1+deb11u2
3.0.2-1
pip/waitress>=2.0.0<3.0.1
3.0.1
Waitress>=2.0.0<3.0.1

Remedy

https://github.com/Pylons/waitress/commit/e4359018537af376cf24bd13616d861e2fb76f65

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2024-49768?

    CVE-2024-49768 is classified as a medium severity vulnerability due to the potential for remote exploitation.

  • How do I fix CVE-2024-49768?

    To fix CVE-2024-49768, upgrade to the latest versions of the `waitress` package as specified in the vendor's advisory.

  • Which software versions are affected by CVE-2024-49768?

    CVE-2024-49768 affects `waitress` versions up to 2.1.2-2 in Debian and all versions between 2.0.0 and 3.0.1 in pip.

  • What are the implications of CVE-2024-49768?

    The implications of CVE-2024-49768 include the risk of denial of service and potential parsing failures when handling pipelined HTTP requests.

  • Is CVE-2024-49768 related to HTTP pipelining?

    Yes, CVE-2024-49768 involves an issue with handling requests using HTTP pipelining when request lookahead is disabled.

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