Application hang via infinite initialization loop
Published Jan 14, 2022 · Updated Sep 16, 2024
Denial of service in Marak colors after 1.4.0 allows attackers to hang Node.js applications when the package is loaded. lib/index.js invokes the American flag routine and then enters a for loop whose counter can never reach Infinity, continuously writing Zalgo text. Any application that loads an affected release reaches the loop during module initialization, blocking its event loop and preventing normal service.
Summary
What happened
Denial of service in Marak colors after 1.4.0 allows attackers to hang Node.js applications when the package is loaded. lib/index.js invokes the American flag routine and then enters a for loop whose counter can never reach Infinity, continuously writing Zalgo text. Any application that loads an affected release reaches the loop during module initialization, blocking its event loop and preventing normal service.
The record
- CVE
- CVE-2021-23567
- Published
- Jan 14, 2022
- Updated
- Sep 16, 2024
- Vendor
- Marak
- Product
- colors
- Classifications
- CWE-835, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 14, 2022CVE publishedPublication date reported by the CVE source.
- Sep 16, 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=next of 1.4.0 <unspecified
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.
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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