CPU exhaustion via unbounded datetime scaling loop
Published May 13, 2021 · Updated Aug 3, 2024
Denial of service in Pydantic before 1.6.2, 1.7.0 through 1.7.3, and 1.8.0 through 1.8.1 allows remote attackers to exhaust CPU. The from_unix_seconds function repeatedly divides an infinite numeric value by 1,000 while its magnitude remains above MS_WATERSHED, so the loop never exits. Exposure requires a consuming application to pass attacker-controlled infinity values into date or datetime validation; one validation call fully occupies one CPU core.
Summary
What happened
Denial of service in Pydantic before 1.6.2, 1.7.0 through 1.7.3, and 1.8.0 through 1.8.1 allows remote attackers to exhaust CPU. The from_unix_seconds function repeatedly divides an infinite numeric value by 1,000 while its magnitude remains above MS_WATERSHED, so the loop never exits. Exposure requires a consuming application to pass attacker-controlled infinity values into date or datetime validation; one validation call fully occupies one CPU core.
The record
- CVE
- CVE-2021-29510
- Published
- May 13, 2021
- Updated
- Aug 3, 2024
- Vendor
- Pydantic
- Product
- Pydantic
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 13, 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=< 1.6.2
- Affected versionversion=>= 1.7.0, < 1.7.4
- Affected versionversion=>= 1.8.0, < 1.8.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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