Описание
File System Bounds Escape
Impact
Clients of FTP servers utilizing ftp-srv hosted on Windows machines can escape the FTP user's defined root folder using the expected FTP commands, for example, CWD and UPDR.
Background
When windows separators exist within the path (\), path.resolve leaves the upper pointers intact and allows the user to move beyond the root folder defined for that user. We did not take that into account when creating the path resolve function.
Patches
None at the moment.
Workarounds
There are no workarounds for windows servers. Hosting the server on a different OS mitigates the issue.
References
Issues: https://github.com/autovance/ftp-srv/issues/167 https://github.com/autovance/ftp-srv/issues/225
For more information
If you have any questions or comments about this advisory: Open an issue at https://github.com/autovance/ftp-srv. Please email us directly; security@autovance.com.
Ссылки
- https://github.com/autovance/ftp-srv/security/advisories/GHSA-pmw4-jgxx-pcq9
- https://nvd.nist.gov/vuln/detail/CVE-2020-26299
- https://github.com/autovance/ftp-srv/issues/167
- https://github.com/autovance/ftp-srv/issues/225
- https://github.com/autovance/ftp-srv/pull/224
- https://github.com/autovance/ftp-srv/commit/457b859450a37cba10ff3c431eb4aa67771122e3
- https://www.npmjs.com/package/ftp-srv
Пакеты
ftp-srv
< 4.4.0
4.4.0
Связанные уязвимости
ftp-srv is an open-source FTP server designed to be simple yet configurable. In ftp-srv before version 4.4.0 there is a path-traversal vulnerability. Clients of FTP servers utilizing ftp-srv hosted on Windows machines can escape the FTP user's defined root folder using the expected FTP commands, for example, CWD and UPDR. When windows separators exist within the path (`\`), `path.resolve` leaves the upper pointers intact and allows the user to move beyond the root folder defined for that user. We did not take that into account when creating the path resolve function. The issue is patched in version 4.4.0 (commit 457b859450a37cba10ff3c431eb4aa67771122e3).
ftp-srv is an open-source FTP server designed to be simple yet configurable. In ftp-srv before version 4.4.0 there is a path-traversal vulnerability. Clients of FTP servers utilizing ftp-srv hosted on Windows machines can escape the FTP user's defined root folder using the expected FTP commands, for example, CWD and UPDR. When windows separators exist within the path (`\`), `path.resolve` leaves the upper pointers intact and allows the user to move beyond the root folder defined for that user. We did not take that into account when creating the path resolve function. The issue is patched in version 4.4.0 (commit 457b859450a37cba10ff3c431eb4aa67771122e3).