Overview
The cyber world is under a significant threat from a recently disclosed vulnerability CVE-2025-52890. This vulnerability resides in the Incus system container and virtual machine manager, specifically affecting versions 6.12 and 6.13. The flaw lies in the generation of nftables rules that inadvertently bypass integral security options, leading to potential ARP spoofing and VM/container spoofing on the same bridge. The reason this vulnerability is of critical concern is because of its potential to compromise entire systems or lead to severe data leakage.
Vulnerability Summary
CVE ID: CVE-2025-52890
Severity: Critical (CVSS: 8.1)
Attack Vector: Network
Privileges Required: None
User Interaction: None
Impact: System compromise or significant data leakage
Affected Products
Escape the Surveillance Era
Most apps won’t tell you the truth.
They’re part of the problem.
Phone numbers. Emails. Profiles. Logs.
It’s all fuel for surveillance.
Ameeba Chat gives you a way out.
- • No phone number
- • No email
- • No personal info
- • Anonymous aliases
- • End-to-end encrypted
Chat without a trace.
Product | Affected Versions
Incus system container manager | 6.12, 6.13
Incus virtual machine manager | 6.12, 6.13
How the Exploit Works
The vulnerability arises from a flaw in Incus’s generation of nftables rules when using an ACL on a device connected to a bridge. These rules partially bypass security options like `security.mac_filtering`, `security.ipv4_filtering`, and `security.ipv6_filtering`. This bypass can lead to Address Resolution Protocol (ARP) spoofing on the bridge. The attacker could potentially exploit this vulnerability to fully spoof another VM/container on the same bridge, leading to unauthorized access or data theft.
Conceptual Example Code
Suppose an attacker has gained access to the network and can send arbitrary packets. Given the vulnerable Incus versions 6.12 or 6.13, they could send a specifically crafted ARP packet like this:
arp -s [target IP] [attacker MAC] -i [bridge interface]This command sends an ARP reply to the target, falsely associating the attacker’s MAC address with the target IP. Once this spoofing is accepted by the target, all traffic meant for the target IP could end up at the attacker’s machine, leading to potential system compromise or data leakage.
Mitigation
To mitigate this vulnerability, it is advised to apply the vendor patch mentioned in commit 254dfd2483ab8de39b47c2258b7f1cf0759231c8. As an alternative or temporary mitigation, a Web Application Firewall (WAF) or Intrusion Detection System (IDS) can be used.