CVE-2025-34096 is a stack-based buffer overflow vulnerability identified in Easy File Sharing HTTP Server version 7.2, developed by EFS Software Inc. The vulnerability arises due to improper validation of the length of the Email parameter in POST requests sent to the /sendemail.ghp endpoint. Specifically, when an attacker sends a crafted POST request containing an overly long Email field, the server fails to restrict operations within the bounds of its memory buffer, leading to memory corruption. This condition enables an unauthenticated remote attacker to execute arbitrary code with the same privileges as the server process, potentially leading to full system compromise. The vulnerability is classified under CWE-119, which pertains to improper restriction of operations within memory buffer bounds. The CVSS 4.0 base score is 9.3, reflecting a critical severity due to the vulnerability’s network attack vector, no required authentication or user interaction, and high impact on confidentiality, integrity, and availability. Although no exploits have been reported in the wild yet, the ease of exploitation and critical impact make this a significant threat. The vulnerability affects only version 7.2 of the software, and no official patches have been linked yet, indicating that mitigation may currently rely on workarounds or access restrictions. Given the nature of the flaw, attackers could leverage this to deploy malware, establish persistent access, or disrupt services.

For European organizations, exploitation of CVE-2025-34096 could result in severe consequences including unauthorized remote code execution, full system compromise, data theft, service disruption, and lateral movement within networks. Organizations using Easy File Sharing HTTP Server 7.2, especially those exposing the /sendemail.ghp endpoint to the internet, are at high risk. Critical sectors such as finance, healthcare, government, and manufacturing could face operational outages and data breaches, potentially violating GDPR and other data protection regulations. The ability for unauthenticated attackers to exploit this vulnerability remotely increases the attack surface significantly. Additionally, compromised servers could be used as footholds for further attacks against European networks or as part of botnets. The lack of known exploits in the wild currently provides a window for proactive defense, but the critical severity score underscores the urgency of mitigation.

1. Immediately restrict external access to the /sendemail.ghp endpoint using network-level controls such as firewalls or web application firewalls (WAFs). 2. Implement strict input validation and length checks on the Email parameter at the application or proxy level to prevent buffer overflow attempts. 3. Monitor network traffic for anomalous POST requests targeting /sendemail.ghp with unusually long Email fields and trigger alerts. 4. If possible, disable or remove the Easy File Sharing HTTP Server 7.2 instance until a vendor patch is available. 5. Engage with EFS Software Inc. for official patches or updates and apply them promptly once released. 6. Conduct internal audits to identify all instances of the vulnerable software within the organization’s environment. 7. Employ endpoint detection and response (EDR) tools to detect potential exploitation attempts or post-exploitation activity. 8. Educate IT and security teams about this vulnerability and ensure incident response plans include scenarios involving remote code execution via web servers. 9. Consider network segmentation to limit the impact of a compromised server. 10. Maintain up-to-date backups and verify recovery procedures to mitigate potential ransomware or destructive payloads deployed through this vulnerability.