Resource exhaustion via unbounded metrics path cardinality
Published Feb 26, 2021 · Updated Aug 3, 2024
Resource exhaustion in Vapor before 4.40.1 allows remote attackers to drain application resources with requests to unique undefined paths. DefaultResponder uses each unmatched request path and method as metric dimensions, creating a distinct counter and timer for every unique value. The attack requires an application that bootstraps a metrics backend; sustained unauthenticated requests exhaust the application or downstream metrics service.
Summary
What happened
Resource exhaustion in Vapor before 4.40.1 allows remote attackers to drain application resources with requests to unique undefined paths. DefaultResponder uses each unmatched request path and method as metric dimensions, creating a distinct counter and timer for every unique value. The attack requires an application that bootstraps a metrics backend; sustained unauthenticated requests exhaust the application or downstream metrics service.
The record
- CVE
- CVE-2021-21328
- Published
- Feb 26, 2021
- Updated
- Aug 3, 2024
- Vendor
- Vapor
- Product
- Vapor
- Classifications
- CWE-400, T1499.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 26, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record 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=<= 4.40.0
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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