CVE-2025-12602 is an out-of-bounds write vulnerability classified under CWE-787 found in Azure Access Technology's BLU-IC2 and BLU-IC4 products up to version 1.19.5. The vulnerability allows an attacker with low privileges and partial authentication to write arbitrarily to the /etc/avahi/services/z9.service file. This file is part of the Avahi service, which is a system for service discovery on a local network via mDNS/DNS-SD. Arbitrary writes to this file could potentially allow an attacker to modify service advertisements or configurations, possibly leading to limited integrity and availability impacts. The CVSS 4.0 vector indicates network attack vector (AV:N), high attack complexity (AC:H), partial authentication required (AT:P), low privileges (PR:L), no user interaction (UI:N), and low impacts on confidentiality, integrity, and availability (VC:L/VI:L/VA:L). The vulnerability is currently published with no known exploits in the wild and no patches yet provided. The affected versions are up to 1.19.5, and the issue is specifically tied to the BLU-IC2 and BLU-IC4 products. Given the nature of the vulnerability, exploitation is non-trivial and requires some level of access and authentication, limiting its immediate risk. However, if exploited, it could be used as part of a broader attack chain to disrupt service discovery or manipulate network services within affected environments.

For European organizations, the impact of CVE-2025-12602 is generally low but should not be dismissed. The arbitrary write to /etc/avahi/services/z9.service could allow attackers to alter service discovery configurations, potentially causing service disruptions or enabling further lateral movement within a network. This could affect availability and integrity of network services relying on Avahi for local discovery. Organizations in sectors with critical infrastructure or those heavily reliant on Azure Access Technology's BLU-IC2/IC4 products might face operational disruptions or targeted attacks aiming to degrade network reliability. The requirement for partial authentication and low privileges means insider threats or compromised accounts could exploit this vulnerability. While confidentiality impact is minimal, the integrity and availability impacts, though low, could have cascading effects in sensitive environments. The absence of known exploits reduces immediate risk but vigilance is necessary to prevent exploitation in high-value targets.

1. Monitor and restrict write permissions on /etc/avahi/services/z9.service to prevent unauthorized modifications. 2. Implement strict access controls and network segmentation to limit access to BLU-IC2 and BLU-IC4 management interfaces. 3. Enforce strong authentication mechanisms to reduce the risk of partial authentication exploitation. 4. Deploy host-based intrusion detection systems (HIDS) to alert on unexpected changes to Avahi service files. 5. Regularly audit and monitor logs related to Avahi and Azure Access Technology products for suspicious activity. 6. Coordinate with Azure Access Technology for timely patch releases and apply updates promptly once available. 7. Conduct internal security awareness training focusing on insider threat risks and credential protection. 8. Consider disabling Avahi service if not required in the environment to reduce attack surface.