Denial of service via unlimited multipart parts
Published Feb 14, 2023 · Updated Mar 10, 2025
Denial of service in Werkzeug before 2.2.3 allows remote attackers to exhaust resources via crafted multipart form data. The multipart form-data parser accepts unlimited fields and file parts, spending CPU and allocating memory and file handles for each part. No authentication or user interaction is required, and sustained requests can block workers or trigger process termination through resource exhaustion.
Summary
What happened
Denial of service in Werkzeug before 2.2.3 allows remote attackers to exhaust resources via crafted multipart form data. The multipart form-data parser accepts unlimited fields and file parts, spending CPU and allocating memory and file handles for each part. No authentication or user interaction is required, and sustained requests can block workers or trigger process termination through resource exhaustion.
The record
- CVE
- CVE-2023-25577
- Published
- Feb 14, 2023
- Updated
- Mar 10, 2025
- Vendor
- Pallets
- Product
- Werkzeug
- Classifications
- CWE-770, CWE-400, T1499
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 14, 2023CVE publishedPublication date reported by the CVE source.
- Mar 10, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.2.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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