CVE-2024-49768

CVE-2024-49768 is a critical-severity vulnerability in Agendaless Waitress with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-367.

Key facts

Description

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.

Frequently asked questions

What is CVE-2024-49768?
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.
How severe is CVE-2024-49768?
CVE-2024-49768 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2024-49768 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2024-49768?
CVE-2024-49768 affects Agendaless Waitress. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2024-49768?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2024-49768 have an EU (EUVD) identifier?
Yes. CVE-2024-49768 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2024-0187.
When was CVE-2024-49768 published?
CVE-2024-49768 was published on 2024-10-29 and last updated on 2026-06-17.

References

Affected products (1)

More vulnerabilities in Agendaless Waitress

All CVEs affecting Agendaless Waitress →

Other CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition) vulnerabilities

Browse all CWE-367 (Time-of-check Time-of-use (TOCTOU) Race Condition) vulnerabilities →