CVE-2025-27258 is an improper access control vulnerability (CWE-284) found in Ericsson Network Manager (ENM) versions prior to 25.1 GA. ENM is a critical network management platform used by telecom operators to manage and orchestrate network elements. The vulnerability allows an attacker with low privileges and network access to escalate their privileges within the ENM system, potentially gaining unauthorized administrative capabilities. The CVSS 4.0 vector indicates the attack vector is adjacent network (AV:A), with low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality (VC:H) but no impact on integrity or availability. This suggests that an attacker who can access the network segment where ENM is deployed can exploit the flaw to access sensitive information or configuration data that should be restricted. No known exploits have been reported yet, but the vulnerability is publicly disclosed and should be treated seriously. The lack of authentication requirement for exploitation increases the risk, especially in environments where network segmentation is weak. The vulnerability is rooted in improper access control mechanisms within ENM, which fail to adequately restrict privilege escalation paths. Since ENM is widely used in telecom infrastructure, the vulnerability could be leveraged to compromise network management operations, potentially leading to broader network security issues if exploited.

For European organizations, especially telecom operators and managed service providers using Ericsson Network Manager, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized access to sensitive network management functions, exposing confidential configuration data and potentially enabling further attacks on the network infrastructure. This could disrupt network operations indirectly by allowing attackers to manipulate network configurations or gather intelligence for subsequent attacks. Given the critical role of ENM in managing telecom networks, the confidentiality breach could have cascading effects on customer data privacy and service reliability. The medium severity rating reflects that while the vulnerability does not directly impact availability or integrity, the elevated privileges gained could be leveraged for more damaging actions. European telecom operators in countries with high Ericsson market penetration are at greater risk, and regulatory compliance frameworks such as GDPR may impose additional consequences if customer data confidentiality is compromised.

The primary mitigation is to upgrade Ericsson Network Manager to version 25.1 GA or later, where this vulnerability is addressed. Until patching is possible, organizations should implement strict network segmentation to isolate ENM systems from untrusted or less secure network segments, limiting access to only authorized personnel and systems. Employing robust access control policies and monitoring network traffic to and from ENM can help detect anomalous activities indicative of exploitation attempts. Additionally, reviewing and tightening user privilege assignments within ENM can reduce the attack surface. Implementing multi-factor authentication (MFA) for ENM access, even if not directly mitigating this vulnerability, enhances overall security posture. Regularly auditing ENM logs and integrating them into a Security Information and Event Management (SIEM) system can facilitate early detection of suspicious privilege escalation attempts. Finally, educating network administrators about this vulnerability and ensuring incident response plans include scenarios involving ENM compromise will improve preparedness.