CVE-2024-34346 — deno
HIGHCVE-2024-34346 is a high-severity (CVSS 8.4) CWE-863 vulnerability in deno. A fix is available for deno — see the affected versions and patch details below.
Deno contains a permission escalation via open of privileged files with missing `--deny` flag
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-34346.
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.
How urgent is this, really
CVE-2024-34346 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,156 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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 | 1.43.1cargo update -p deno --precise 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update deno to 1.43.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-34346 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-34346 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2024-34346. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-34346 in your dependencies?
O3 Security finds CVE-2024-34346 across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.