CVE-2023-53740 is an authentication bypass vulnerability classified under CWE-862 affecting the Screen SFT DAB 1.9.3 software used in DB Elettronica Telecomunicazioni SpA's Compact Radio DAB Transmitter series. The vulnerability arises because the userManager.cgx endpoint improperly authorizes requests, allowing attackers to bypass authentication controls. By sending a specially crafted JSON request containing a new administrator password hashed with MD5, an attacker can overwrite the existing admin password without providing the current credentials. This flaw effectively grants unauthorized administrative access to the device, enabling full control over its configuration and operation. The vulnerability has a CVSS 4.0 base score of 8.6, indicating high severity, with attack vector being adjacent network (AV:A), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction needed (UI:P). The impact metrics show high confidentiality and integrity impact, with low availability impact. The vulnerability does not require physical access or authentication, making it exploitable remotely within the network segment. While no public exploits are reported yet, the straightforward exploitation method and critical access gained pose a significant risk to affected systems. The Screen SFT DAB series is used in digital audio broadcasting infrastructure, making this vulnerability particularly relevant to broadcast operators and telecom providers. The lack of available patches at the time of publication necessitates immediate compensating controls to mitigate risk.

For European organizations, especially broadcasters and telecom operators relying on DB Elettronica's Screen SFT DAB transmitters, this vulnerability poses a serious risk. Unauthorized administrative access can lead to manipulation or disruption of digital audio broadcast services, impacting service availability and integrity. Attackers could alter broadcast content, disable transmitters, or use compromised devices as pivot points for further network intrusion. Confidentiality of administrative credentials and device configurations is also at risk, potentially exposing sensitive operational data. Given the critical role of DAB transmitters in public communication infrastructure, exploitation could affect large audiences and critical information dissemination. The impact extends to regulatory compliance, as service disruptions or unauthorized control may violate EU telecom and data protection regulations. The vulnerability's ease of exploitation within local or adjacent networks increases risk in environments with insufficient network segmentation or access controls. Organizations may face reputational damage and operational losses if attacks occur during critical broadcast periods.

1. Immediately restrict network access to the Screen SFT DAB devices by implementing strict firewall rules and network segmentation to limit access to trusted management hosts only. 2. Monitor network traffic for unusual or unauthorized requests to the userManager.cgx endpoint, focusing on JSON payloads attempting password changes. 3. Enforce strong physical and logical access controls to prevent unauthorized local or network access to the devices. 4. Disable or restrict remote management interfaces if not required, or enforce VPN and multi-factor authentication for remote access. 5. Regularly audit device configurations and administrator accounts for unauthorized changes. 6. Engage with DB Elettronica Telecomunicazioni SpA for official patches or firmware updates addressing this vulnerability and apply them promptly once available. 7. Implement intrusion detection/prevention systems (IDS/IPS) tuned to detect exploitation attempts targeting this vulnerability. 8. Conduct security awareness training for operational staff to recognize and report suspicious activities related to broadcast infrastructure. 9. Develop and test incident response plans specific to broadcast equipment compromise scenarios. 10. Consider deploying network anomaly detection solutions to identify deviations in device behavior that may indicate compromise.