EUVD-2025-19114
GHSA-p7fw-vjjm-2rwp
CVSS Vector
CVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:H
Lifecycle Timeline
4Description
Incus is a system container and virtual machine manager. When using an ACL on a device connected to a bridge, Incus versions 6.12 and 6.13generates nftables rules that partially bypass security options `security.mac_filtering`, `security.ipv4_filtering` and `security.ipv6_filtering`. This can lead to ARP spoofing on the bridge and to fully spoof another VM/container on the same bridge. Commit 254dfd2483ab8de39b47c2258b7f1cf0759231c8 contains a patch for the issue.
Analysis
CVE-2025-52890 is a network-layer security bypass in Incus 6.12 and 6.13 where improper nftables rule generation on bridge-connected ACL devices allows attackers to circumvent MAC filtering, IPv4 filtering, and IPv6 filtering security controls. This enables ARP spoofing and full VM/container impersonation on the same bridge. The vulnerability requires administrative privilege and local network access but results in high confidentiality and availability impact across the container/VM infrastructure.
Technical Context
Incus is a system container and virtual machine manager that inherits from LXD. The vulnerability exists in the nftables firewall rule generation logic when Access Control Lists (ACLs) are applied to devices connected to network bridges. Nftables is a successor to iptables and manages Linux kernel netfilter rules. The root cause (CWE-863: Incorrect Authorization) stems from incomplete implementation of security filtering rules—the generated nftables ruleset partially bypasses the intended security.mac_filtering, security.ipv4_filtering, and security.ipv6_filtering options. This allows ARP (Address Resolution Protocol) spoofing, which operates at Layer 2, to succeed despite Layer 2/3 filtering policies that should prevent it. The vulnerability affects CPE:2.3:a:linuxcontainers:incus:6.12:*:*:*:*:*:*:* and CPE:2.3:a:linuxcontainers:incus:6.13:*:*:*:*:*:*:*.
Affected Products
Incus (['6.12', '6.13'])
Remediation
Upgrade to Incus version after 6.13 (e.g., 6.14 or later) once released, or apply the specific commit patch to 6.12/6.13 installations Workaround: Review and remove ACL policies from bridge device configurations until patched version is available Mitigation: Use VLAN segmentation or separate bridges for untrusted guest VMs to prevent ARP spoofing impact across trust boundaries Mitigation: Limit who can create and manage VMs/containers and configure ACLs, reducing attack surface since PR:H is required
Priority Score
Vendor Status
Ubuntu
Priority: Medium| Release | Status | Version |
|---|---|---|
| jammy | DNE | - |
| noble | needs-triage | - |
| upstream | needs-triage | - |
| oracular | ignored | end of life, was needs-triage |
| questing | needs-triage | - |
| plucky | ignored | end of life, was needs-triage |
Debian
| Release | Status | Fixed Version | Urgency |
|---|---|---|---|
| trixie (security), trixie | fixed | 6.0.4-2+deb13u4 | - |
| forky | fixed | 6.0.5-8 | - |
| sid | fixed | 6.0.6-1 | - |
| (unstable) | not-affected | - | - |
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External POC / Exploit Code
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