Application crash via malformed language tag parsing
Published Dec 26, 2022 · Updated Apr 14, 2025
Denial of service in golang.org/x/text before 0.3.7 allows remote attackers to crash applications parsing malformed BCP 47 language tags. The language package's Parse path mishandles index calculations and reads outside a slice boundary instead of rejecting an incorrectly formatted tag. Exposure requires a consuming application to pass attacker-controlled language tags to Parse, MatchStrings, MustParse, or ParseAcceptLanguage; the resulting panic interrupts that application process.
Summary
What happened
Denial of service in golang.org/x/text before 0.3.7 allows remote attackers to crash applications parsing malformed BCP 47 language tags. The language package's Parse path mishandles index calculations and reads outside a slice boundary instead of rejecting an incorrectly formatted tag. Exposure requires a consuming application to pass attacker-controlled language tags to Parse, MatchStrings, MustParse, or ParseAcceptLanguage; the resulting panic interrupts that application process.
The record
- CVE
- CVE-2021-38561
- Published
- Dec 26, 2022
- Updated
- Apr 14, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-125, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Dec 26, 2022CVE publishedPublication date reported by the CVE source.
- Apr 14, 2025Record updatedLatest update available in the CVE record.
Exploitability
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Published CVSS scores
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Attacks
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Technologies
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