Vulnerability feed

Executive summary

A flaw in the Incus command-line tool lets a compromised virtual machine write arbitrary files onto the machine running the Incus CLI when an operator performs a recursive file pull from that VM. The advisory rates it Moderate with a CVSS 3.1 base score of 5.8, and the fix is to upgrade to Incus version 7.5.0 or later, since the affected versions are listed as less than v7.5.0.

Technical summary

This is a link-following weakness (CWE-59) in sftpRecursivePullFile in the incus file pull -r code path. A malicious incus-agent inside a guest VM can return the same directory entry twice, first as a symlink and then as a directory or regular file, causing the client to write through the symlink outside the target directory. The attacker needs root inside the VM, and the operator must run a recursive pull from that VM, which is the required user interaction; the CVSS vector is AV:N/AC:H/PR:L/UI:R/S:C/C:N/I:H/A:N. Affected versions are stated as Incus before 6.0.7, 6.1.0 before 7.0.2, and 7.1.0 before 7.5.0, and the Go module advisory lists affected versions as less than v7.5.0 with patched versions at v7.5.0 or later. Containers are stated as not affected. The advisory's only workaround is to avoid incus file pull -r from untrusted VMs or to run it as an unprivileged user into a dedicated directory. No detection guidance is stated, and no CVE ID is assigned in the advisory text.

Summaries are generated by AI from the linked advisory text. Confirm versions and fixes at the source.

Summarized from github.com/lxc/incus/security/advisories/GHSA-wfvq-qh87-gm4j

Impact if exploited

How it is exploited

Attack vector

Network

Attack complexity

Low

Attack requirements

Present

Privileges required

Low

User interaction

Passive

CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:P/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affects

lxcIncuslxc incusIncusincus CLI