CVE-2025-34180 affects NetSupport Manager versions earlier than 14.12.0001 and involves improper storage of the shared Gateway Key used for authentication between Manager/Control, Client, and Connectivity Server components. Instead of securely hashing or encrypting the key, the software uses a reversible encoding scheme, effectively storing the key in a recoverable format. An attacker who gains access to a deployed client configuration file can decode the stored Gateway Key to obtain its plaintext value. With possession of this key, the attacker can authenticate to NetSupport Manager connectivity services, bypassing normal authentication controls. This enables unauthorized remote control over systems managed by the compromised key, potentially allowing lateral movement, data exfiltration, or disruption of managed endpoints. The vulnerability requires local access to configuration files, which may be obtained through other means such as phishing, malware, or insider threats. No user interaction or elevated privileges beyond local read access are necessary, increasing the risk in environments where endpoint security is weak. The CVSS 4.0 vector (AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H) indicates a local attack vector with low complexity, no attack prerequisites, and high impact on confidentiality and integrity. Although no known exploits are currently in the wild, the vulnerability poses a significant risk to organizations relying on NetSupport Manager for remote administration, especially in sectors where remote control of endpoints is critical.

For European organizations, exploitation of this vulnerability could lead to unauthorized remote access and control of critical systems, resulting in potential data breaches, operational disruption, and loss of trust. Sectors such as finance, healthcare, government, and critical infrastructure that use NetSupport Manager for remote support and management are particularly at risk. The ability to recover the Gateway Key compromises the confidentiality and integrity of the authentication mechanism, allowing attackers to impersonate legitimate management clients. This could facilitate lateral movement within networks, enabling attackers to escalate privileges or exfiltrate sensitive data. Additionally, compromised systems could be manipulated to disrupt services or deploy further malware. The local access requirement somewhat limits the attack surface but does not eliminate risk, especially in environments with insufficient endpoint protection or insider threats. The high CVSS score reflects the potential for significant impact if exploited. European organizations must consider the risk of supply chain attacks or insider misuse that could leverage this vulnerability.

Organizations should immediately upgrade NetSupport Manager to version 14.12.0001 or later, where this vulnerability is addressed by eliminating reversible encoding of the Gateway Key. Until patching is possible, restrict access to client configuration files by enforcing strict file system permissions and using endpoint protection solutions to detect unauthorized access attempts. Implement network segmentation to limit the exposure of NetSupport Manager connectivity services. Monitor logs for unusual authentication attempts or remote control sessions. Employ strong endpoint security controls to prevent malware or insider threats from accessing configuration files. Consider rotating the Gateway Key after patching to invalidate any potentially compromised keys. Additionally, conduct regular audits of remote management tools and credentials to ensure compliance with security policies. Educate users and administrators about the risks of local file exposure and enforce least privilege principles to reduce attack vectors.