CVE-2025-56424 is a vulnerability identified in Insiders Technologies GmbH's e-invoice pro software versions prior to release 1 Service Pack 2. The flaw allows a remote attacker to cause a denial of service (DoS) condition by submitting a specially crafted script to the application. This vulnerability is classified under CWE-400, which pertains to uncontrolled resource consumption leading to service disruption. The attack vector is network-based (AV:N), requires no privileges (PR:N), and no user interaction (UI:N), making exploitation straightforward for an unauthenticated attacker. The vulnerability impacts availability (A:H) but does not affect confidentiality or integrity. The absence of known exploits in the wild suggests it has not yet been weaponized, but the high CVSS score of 7.5 indicates significant risk if exploited. The lack of a patch at the time of publication means organizations must rely on interim mitigations until Service Pack 2 is released. The vulnerability could disrupt e-invoicing services, potentially halting invoice processing and impacting business continuity.

For European organizations, especially those relying on Insiders Technologies GmbH e-invoice pro software, this vulnerability poses a risk of service outages due to denial of service attacks. Disruption of e-invoicing can delay financial transactions, affect cash flow, and impair compliance with tax and regulatory reporting requirements. Industries with high volumes of electronic invoicing, such as manufacturing, retail, and logistics, may experience operational delays. Public sector entities and financial institutions using this software might face increased risk of service unavailability, impacting citizen services and financial operations. The ease of remote exploitation without authentication increases the threat landscape, potentially allowing attackers to disrupt multiple organizations simultaneously. Although no data confidentiality or integrity is compromised, the availability impact alone can cause significant operational and reputational damage.

Organizations should prioritize applying the official Service Pack 2 update from Insiders Technologies GmbH as soon as it becomes available to remediate this vulnerability. Until then, network administrators should implement intrusion detection and prevention systems (IDS/IPS) to monitor and block suspicious scripts targeting the e-invoice pro application. Rate limiting and traffic anomaly detection can help mitigate resource exhaustion attempts. Restricting access to the e-invoicing service to trusted IP ranges or VPNs can reduce exposure. Regularly reviewing application logs for unusual script submissions and conducting penetration testing focused on resource exhaustion scenarios will aid in early detection. Additionally, organizations should ensure robust backup and recovery procedures to minimize downtime impact in case of successful DoS attacks.