Disclosure and denial of service via marker expansion
Published Dec 4, 2023 · Updated Feb 13, 2025
Interpretation conflict in fish-shell fish before 3.6.2 allows local users to disclose variables or interrupt the shell via command substitution. The str2wcs_internal conversion path admits fish-reserved Unicode code points from subprocess output instead of encoding them, so the parser treats them as wildcard or expansion markers. Exploitation requires user interaction with a command substitution consuming output influenced by local users; code execution is not reported, while variable and large brace expansion can disclose data or exhaust resources.
Summary
What happened
Interpretation conflict in fish-shell fish before 3.6.2 allows local users to disclose variables or interrupt the shell via command substitution. The str2wcs_internal conversion path admits fish-reserved Unicode code points from subprocess output instead of encoding them, so the parser treats them as wildcard or expansion markers. Exploitation requires user interaction with a command substitution consuming output influenced by local users; code execution is not reported, while variable and large brace expansion can disclose data or exhaust resources.
The record
- CVE
- CVE-2023-49284
- Published
- Dec 4, 2023
- Updated
- Feb 13, 2025
- Vendor
- fish-shell
- Product
- fish
- Classifications
- CWE-436, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Dec 4, 2023CVE publishedPublication date reported by the CVE source.
- Feb 13, 2025Record 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=< 3.6.2
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.
Public exploit references
- GitHub command-substitution disclosure demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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