CVE-2025-14186 identifies a basic cross-site scripting vulnerability in the Grandstream GXP1625 IP phone firmware version 1.0.7.4. The vulnerability resides in an unspecified function within the /cgi-bin/api.values.post CGI endpoint, specifically in the handling of the vpn_ip argument on the Network Status Page. By manipulating this parameter, an attacker can inject arbitrary JavaScript code that executes in the context of the device's web interface. The vulnerability is remotely exploitable without requiring authentication, although user interaction is necessary to trigger the malicious script, classifying it as a reflected or stored XSS depending on the context. The exploit allows attackers to perform actions such as session hijacking, credential theft, or redirecting users to malicious sites, compromising the confidentiality and integrity of the device and potentially the broader network. The vendor was contacted prior to public disclosure but did not respond or provide a patch, increasing the risk of exploitation. The CVSS v4.0 score is 5.1 (medium severity), reflecting the ease of remote exploitation but limited impact on availability and requiring user interaction. No known exploits in the wild have been reported yet, but the public availability of the exploit code raises the likelihood of attacks. The vulnerability affects a widely deployed VoIP device used in enterprise telephony, making it a relevant concern for organizations relying on Grandstream hardware for communication.

For European organizations, this vulnerability poses a moderate risk primarily to the confidentiality and integrity of communications and device management. Exploitation could lead to unauthorized access to the device’s web interface, enabling attackers to hijack sessions, steal credentials, or inject malicious content that could spread within the corporate network. This is particularly critical for sectors heavily dependent on VoIP communications such as finance, healthcare, and government agencies. Compromised IP phones could serve as entry points for lateral movement or espionage. Additionally, the lack of vendor response and patch availability increases exposure time. Organizations with remote or distributed workforces using these devices may face higher risk due to broader attack surfaces. While availability impact is low, the potential for data leakage and trust erosion in communication systems is significant. The public exploit availability may lead to opportunistic attacks, especially targeting less-secured networks or devices with default configurations.

To mitigate this vulnerability, European organizations should implement strict network segmentation to isolate IP phones from critical infrastructure and sensitive data networks. Access to the device’s web interface should be restricted to trusted management networks using firewall rules or VPNs. Employ web application firewalls (WAFs) capable of detecting and blocking XSS payloads targeting the /cgi-bin/api.values.post endpoint. Regularly audit and monitor device logs for unusual access patterns or injection attempts. Disable or limit web interface access if not required for daily operations. Where possible, replace or upgrade affected devices to models or firmware versions not impacted by this vulnerability, even if official patches are unavailable. Educate users about the risks of interacting with suspicious links or prompts originating from IP phone interfaces. Implement multi-factor authentication for device management portals if supported. Finally, maintain an incident response plan to quickly address any detected exploitation attempts.