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LOW

Deno's --deny-write check does not prevent permission bypass

Published Oct 8, 2025

Description

Deno is a JavaScript, TypeScript, and WebAssembly runtime. In versions prior to 2.5.3 and 2.2.15, `Deno.FsFile.prototype.utime` and `Deno.FsFile.prototype.utimeSync` are not limited by the permission model check `--deny-write=./`. It's possible to change to change the access (`atime`) and modification (`mtime`) times on the file stream resource even when the file is opened with `read` only permission (and `write`: `false`) and file write operations are not allowed (the script is executed with `--deny-write=./`). Similar APIs like `Deno.utime` and `Deno.utimeSync` require `allow-write` permission, however, when a file is opened, even with read only flags and deny-write permission, it's still possible to change the access (`atime`) and modification (`mtime`) times, and thus bypass the permission model. Versions 2.5.3 and 2.2.15 fix the issue.

Affected products

Remediation

No remediation recorded yet.

References (8)

Change history (0)

No recorded changes yet.

Sources
CVE.org / MITRE
Status PUBLISHED
Assigner GitHub_M
Published Oct 8, 2025
Updated Oct 8, 2025
Reserved Sep 30, 2025
CISA Vulnrichment
Updated Oct 8, 2025
NVD
Status Analyzed
Modified Jun 17, 2026
Red Hat
Severity n/a
Public date n/a
ENISA EUVD
Assigner GitHub_M
Published Oct 8, 2025
Updated Oct 8, 2025
Exploited since n/a
EUVD-2025-31878 GHSA-VG2R-RMGP-CGQJ