PyPI: werkzeug
CVE-2023-46136
Safety vulnerability ID: SFTY-20231025-16698
Safety legacy ID: pyup.io-71595
Werkzeug is a comprehensive WSGI web application library. If an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests.
Overview
Werkzeug DoS: High resource usage when parsing multipart/form-data containing a large part with CR/LF character at the beginning
Advisory
Werkzeug is a comprehensive WSGI web application library. If an upload of a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests.
How to Fix
Mitigation and Workarounds
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Vulnerable Functions
Functions linked to known vulnerabilities.
References
- https://getsafety.com/vulnerabilities/SFTY-20231025-16698/CVE-2023-46136
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-46136
- https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2
- https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw
- https://github.com/pallets/werkzeug/security/advisories/GHSA-hrfv-mqp8-q5rw
- https://github.com/pallets/werkzeug/commit/b1916c0c083e0be1c9d887ee2f3d696922bfc5c1
- https://nvd.nist.gov/vuln/detail/CVE-2023-46136
- https://github.com/pallets/werkzeug/commit/f3c803b3ade485a45f12b6d6617595350c0f03e2
- https://github.com/pypa/advisory-database/tree/main/vulns/werkzeug/PYSEC-2023-221.yaml
- https://github.com/pallets/werkzeug/commit/f2300208d5e2a5076cbbb4c2aad71096fd040ef9
- https://security.netapp.com/advisory/ntap-20231124-0008
- https://github.com/advisories/GHSA-hrfv-mqp8-q5rw
Verified by Safety
Our Cybersecurity Intelligence Team reviewed this vulnerability. We combine public data with our own research to find issues not yet reported to public sources.
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