CVE-2025-27917 is a vulnerability identified in AnyDesk remote desktop software versions prior to 9.0.5 on Windows, 9.0.1 on macOS, 7.0.0 on Linux, 7.1.2 on iOS, and 8.0.0 on Android. The root cause is an incorrect deserialization process within the software that leads to failed memory allocation and a NULL pointer dereference. This flaw can be triggered remotely without any authentication or user interaction, resulting in a denial of service (DoS) condition where the AnyDesk application crashes or becomes unresponsive, thereby denying legitimate users remote access. The vulnerability is classified under CWE-476 (NULL Pointer Dereference), which typically causes application crashes and service interruptions. The CVSS v3.1 base score is 7.5, reflecting high severity due to network attack vector, low attack complexity, no privileges required, and no user interaction needed. Although no known exploits have been reported in the wild, the vulnerability poses a significant risk to availability, especially for organizations dependent on AnyDesk for critical remote access. The issue affects multiple operating systems, increasing the scope and potential impact. The vulnerability was reserved in March 2025 and published in November 2025, but no official patches or advisories are linked in the provided data, indicating organizations must verify and apply the latest AnyDesk updates proactively.

For European organizations, the primary impact of CVE-2025-27917 is on the availability of remote desktop services provided by AnyDesk. Disruption of remote access can hinder business continuity, especially for companies with distributed workforces or those relying on remote support and administration. Critical sectors such as finance, healthcare, and government services that utilize AnyDesk for secure remote operations could experience operational delays or outages. The vulnerability does not compromise confidentiality or integrity directly but can cause denial of service, potentially leading to loss of productivity and increased support costs. Given the cross-platform nature of the vulnerability, organizations using AnyDesk on various devices are at risk. The lack of required authentication or user interaction lowers the barrier for attackers to exploit this flaw remotely, increasing the threat level. Although no active exploitation is reported, the high severity score and ease of exploitation necessitate urgent remediation to prevent potential attacks that could disrupt services across Europe.

Organizations should immediately verify the AnyDesk versions deployed across all platforms and upgrade to the fixed versions: 9.0.5 or later for Windows, 9.0.1 or later for macOS, 7.0.0 or later for Linux, 7.1.2 or later for iOS, and 8.0.0 or later for Android. If immediate patching is not feasible, consider restricting AnyDesk network access via firewall rules to trusted IP addresses and monitoring network traffic for unusual connection attempts. Implement network segmentation to isolate critical systems from endpoints running vulnerable AnyDesk versions. Enable logging and alerting on AnyDesk service crashes or restarts to detect potential exploitation attempts. Educate IT staff about this vulnerability and incorporate it into incident response plans. Regularly check AnyDesk vendor advisories for updates or patches. Additionally, consider alternative remote access solutions temporarily if patching is delayed. Employ endpoint protection solutions capable of detecting anomalous application behavior related to memory errors or crashes.