CVSS 8.4 · High EPSS 0,45%
Kerentanan Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') pada canonical multipass. Skor CVSS 3.1 8.4 (High) menurut ubuntu.com.
An issue was discovered in Canonical Multipass before version 1.16.3. The host-side SFTP server component (sshfs_server), which executes with root privileges on the host, contains a path containment bypass vulnerability within its validate_path function in src/sshfs_mount/sftp_server.cpp. The function performs a plain string prefix comparison on requested paths without path separator validation or dot-dot (..) normalization. A local attacker with root privileges inside a guest virtual machine can bypass the FUSE layer by injecting raw SFTP frames (such as an SSH_FXP_OPEN request) directly into the sshfs_server process stdin/stdout pipes via procfs. By supplying a path containing directory traversal sequences that match the allowed mount prefix, the attacker can force the host-side root process to resolve the traversal and open files outside the designated mount boundary. This allows a guest-side user to read arbitrary files on the host filesystem, resulting in a virtual machine escape.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| canonical | multipass | Semua versi sebelum 1.16.3 |