CVE-2024-34346: Deno is a JavaScript, TypeScript, and WebAssembly runtime with secure defaults. The Deno sandbox may be unexpectedly weakened by allowing file read/wr...

Description

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.

Metrics

CVSS 3.1

9/10

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

0.37%

28.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-863

Affected Software

Vendor	Product	Versions
Deno	Deno	< 1.43.1

References

https://github.com/denoland/deno/security/advisories/GHSA-23rx-c3g5-hv9wVendor Advisory
https://github.com/denoland/deno/security/advisories/GHSA-23rx-c3g5-hv9wVendor Advisory

Timeline

Published: May 7, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-34346?

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.

How severe is CVE-2024-34346?

CVE-2024-34346 has a CVSS score of 9/10 (CRITICAL severity). The EPSS model estimates a 0.37% probability of exploitation in the next 30 days.

How do I fix CVE-2024-34346?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.