GHSA-23rx-c3g5-hv9w
HIGHDeno permission escalation vulnerability via open of privileged files with missing `--deny` flag
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
denoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
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.
Impact
Users who run code with --allow-read or --allow-write may unexpectedly end up granting additional permissions via file-system operations.
Patches
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.
Workarounds
The security sandbox in previous versions of Deno allows for denial of access to these files, but it requires an explicit addition of deny flags: --deny-read=/dev --deny-read=/sys --deny-read=/proc --deny-read=/etc --deny-write=/dev --deny-write=/sys --deny-write=/proc --deny-write=/etc. Note that symlinks in allowed locations may defeat this protection in earlier versions of Deno.
Reporters
This vulnerability was reported by a number of analysts. Thanks to [email protected], [email protected], @leesh3288, and @cristianstaicu for their reports and analysis.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | deno | all versions | 1.43.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for deno. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update deno to 1.43.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-23rx-c3g5-hv9w is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-23rx-c3g5-hv9w is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-23rx-c3g5-hv9w. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-23rx-c3g5-hv9w in your dependencies?
O3 detects GHSA-23rx-c3g5-hv9w across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.