Memory disclosure or crash via IDNA buffer overread
Published Jul 12, 2021 · Updated Apr 30, 2025
Out-of-bounds read in Node.js libuv before 12.22.2, 14.17.2, or 16.4.1 allows remote attackers to disclose memory or crash processes. The uv__idna_toascii() punycode decoder increments and dereferences its input pointer without first ensuring that it remains before the buffer-end pointer. Reachability requires an application to pass an attacker-controlled hostname to dns.lookup(); a crafted lookup can expose adjacent process memory or terminate the process.
Summary
What happened
Out-of-bounds read in Node.js libuv before 12.22.2, 14.17.2, or 16.4.1 allows remote attackers to disclose memory or crash processes. The uv__idna_toascii() punycode decoder increments and dereferences its input pointer without first ensuring that it remains before the buffer-end pointer. Reachability requires an application to pass an attacker-controlled hostname to dns.lookup(); a crafted lookup can expose adjacent process memory or terminate the process.
The record
- CVE
- CVE-2021-22918
- Published
- Jul 12, 2021
- Updated
- Apr 30, 2025
- Vendor
- Node.js
- Product
- Node.js
- Classifications
- CWE-125, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 12, 2021CVE publishedPublication date reported by the CVE source.
- Apr 30, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=10.0 <10.*
- Affected versionversion=11.0 <11.*
- Affected versionversion=12.0 <12.22.2
- Affected versionversion=13.0 <13.*
- Affected versionversion=14.0 <14.17.2
- Affected versionversion=15.0 <15.*
- Affected versionversion=16.0 <16.4.1
- Affected versionversion=4.0 <4.*
- Affected versionversion=5.0 <5.*
- Affected versionversion=6.0 <6.*
- Affected versionversion=7.0 <7.*
- Affected versionversion=8.0 <8.*
- Affected versionversion=9.0 <9.*
What conditions does exploitation require?
What is affected?
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.
Public exploit references
- HackerOne report 1209681 exploit artifactproof of concept · unverified
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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