CVE-2025-25235 is a high-severity Server-Side Request Forgery (SSRF) vulnerability identified in the Omnissa Secure Email Gateway (SEG) product. This vulnerability affects SEG versions prior to 2.32 on Windows and versions prior to 2503 on UAG platforms. SSRF vulnerabilities allow an attacker to abuse the server's functionality to send crafted HTTP requests from the vulnerable server to internal or external network resources that would otherwise be inaccessible. In this case, the Omnissa SEG improperly validates or restricts URLs or network requests, enabling an unauthenticated attacker to route arbitrary network traffic through the SEG server. The CVSS 3.1 base score of 8.6 reflects the vulnerability's network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and a scope change (S:C) indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact is rated as high on confidentiality (C:H), with no impact on integrity or availability. This suggests that an attacker can leverage the SSRF to access sensitive internal network resources or services, potentially exfiltrating confidential information or performing reconnaissance. However, the vulnerability does not directly allow modification or disruption of data or services. No known public exploits or patches are currently available, but the vulnerability has been officially published and reserved since early 2025. The CWE-918 classification confirms the nature of the SSRF flaw. Given that Omnissa SEG is a secure email gateway product, it is typically deployed at network perimeters to filter and secure email traffic, making it a critical security control point. Exploiting this SSRF could allow attackers to pivot into internal networks, bypassing perimeter defenses and accessing internal services that are not exposed externally. This could facilitate further attacks such as data theft, lateral movement, or reconnaissance within the victim's network.

For European organizations, the impact of CVE-2025-25235 is significant due to the widespread use of secure email gateways as a frontline defense against email-borne threats. Successful exploitation could allow attackers to bypass network segmentation and access internal resources, potentially exposing sensitive personal data protected under GDPR and other privacy regulations. Confidentiality breaches could lead to regulatory penalties, reputational damage, and loss of customer trust. Additionally, internal services accessed via SSRF could include databases, internal APIs, or management consoles, increasing the risk of further compromise. The lack of required authentication and user interaction means attackers can exploit this vulnerability remotely and autonomously, increasing the threat level. European organizations in sectors such as finance, healthcare, government, and critical infrastructure are particularly at risk given their reliance on secure email gateways and the sensitivity of their data. The SSRF could also be leveraged as a stepping stone for advanced persistent threats (APTs) targeting European entities, especially in the context of geopolitical tensions. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the high CVSS score and scope change indicate that the vulnerability could be weaponized effectively once exploit code becomes available.

European organizations should immediately assess their deployment of Omnissa Secure Email Gateway products and identify versions prior to 2.32 on Windows and prior to 2503 on UAG. Although no official patches are currently listed, organizations should monitor Omnissa's advisories closely for forthcoming security updates and apply them promptly once available. In the interim, network-level mitigations can reduce risk: restrict outbound HTTP/HTTPS traffic from the SEG server to only necessary external endpoints using firewall rules; implement strict egress filtering to prevent unauthorized internal network access; and employ network segmentation to isolate the SEG from sensitive internal systems. Additionally, review and harden SEG configuration settings to disable any unnecessary URL fetching or proxying features that could be abused. Deploying Web Application Firewalls (WAFs) or Intrusion Detection/Prevention Systems (IDS/IPS) with SSRF detection capabilities can help identify and block suspicious requests. Conduct thorough logging and monitoring of SEG network activity to detect anomalous outbound requests indicative of SSRF exploitation attempts. Finally, educate security teams about SSRF risks and prepare incident response plans to quickly contain and remediate potential exploitation.