CVEvulnerability

CVE-2024-49768

4.8 MEDIUM Published 2024-10-29 Modified 2026-06-17 Official page ↗
Status
Analyzed
Published
2024-10-29
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
9.1 CRITICAL — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
CVSS 3.1 ([email protected])
4.8 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
Weaknesses
CWE-367, CWE-444

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.

Affected configurations

• agendaless waitress (>= 2.0.0 < 3.0.1)

Related

Weakness · CWE (2)

  • CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition weakness
  • CWE-444 Inconsistent Interpretation of HTTP Requests weakness

References