CVE intelligence and bounded remediation

CVE-2024-34346 — Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults

Critical CVSS 9

Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. The Deno sandbox may be unexpectedly weakened by allowing file read/write access to privileged files in various locations on Unix and Windows platforms. For example, reading `/proc/self/environ` may provide access equivalent to `--allow-env`, and writing `/proc/self/mem` may provide access equivalent to `--allow-all`. Users who grant read and write access to the entire filesystem may not realize that these access to these files may have additional, unintended consequences. The documentation did not reflect that this practice should be undertaken to increase the strength of the security sandbox. Users who run code with `--allow-read` or `--allow-write` may unexpectedly end up granting additional permissions via file-system operations. Deno 1.43 and above require explicit `--allow-all` access to read or write `/etc`, `/dev` on unix platform (as well as `/proc` and `/sys` on linux platforms), and any path starting with `\\` on Windows.

Severity
Critical
CVSS
9 (3.1)
Published
2024-05-07
CISA KEV
Not currently listed
Ecosystem
windows/system
Weaknesses
CWE-863

Affected products

  • deno / deno

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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