Secret disclosure via ignored environment deny list
Published Jun 4, 2025 · Updated Jun 4, 2025
Information disclosure in Deno before 2.1.13 and 2.2.0 through 2.2.12 allows attackers to read denied environment variables. Deno.env.toObject() invokes a check-all permission path that treated unrestricted --allow-env as fully granted and skipped the --deny-env list. Exploitation requires attacker-controlled code to run with broad environment access plus a deny list, exposing secrets held in the process environment.
Summary
What happened
Information disclosure in Deno before 2.1.13 and 2.2.0 through 2.2.12 allows attackers to read denied environment variables. Deno.env.toObject() invokes a check-all permission path that treated unrestricted --allow-env as fully granted and skipped the --deny-env list. Exploitation requires attacker-controlled code to run with broad environment access plus a deny list, exposing secrets held in the process environment.
The record
- CVE
- CVE-2025-48934
- Published
- Jun 4, 2025
- Updated
- Jun 4, 2025
- Vendor
- Deno Land Inc.
- Product
- Deno
- Classifications
- CWE-201, T1005
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 4, 2025CVE publishedPublication date reported by the CVE source.
- Jun 4, 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=< 2.1.13
- Affected versionversion=>= 2.2.0, < 2.2.13
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.
Weakness, pattern, technique
Public exploit references
- Deno.env.toObject deny-list bypass proof of conceptproof 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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