Vulnerability in Agendaless Waitress
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.
Vulnerability class: TOCTOU (Time-of-Check to Time-of-Use)
EPSS: 0.005 (39.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Agendaless Waitress
- Pylons Waitress — versions >= 2.0.0, < 3.0.1
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
Frequently asked questions
- What is CVE-2024-49768?
- CVE-2024-49768 is a critical-severity vulnerability in Agendaless Waitress, classified under Time-of-check Time-of-use (TOCTOU) Race Condition. CVSS score: 9.1/10. Published 2024-10-29.
- How severe is CVE-2024-49768?
- Critical severity. CVSS v3 base score is 9.1 out of 10.
- Is CVE-2024-49768 known to be exploited?
- 6 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.