CVE-2025-47890 is a vulnerability categorized as an improper access control issue leading to an open redirect (CWE-601) in Fortinet's FortiOS, FortiProxy, and FortiSASE products. The affected versions include FortiOS 6.4.0 through 7.6.2, FortiProxy 7.0 through 7.6.3, and FortiSASE 25.2.a. The vulnerability allows an unauthenticated attacker to craft specially formed HTTP requests that cause the affected devices to redirect users to untrusted external websites. This redirection flaw can be exploited without authentication but requires user interaction, such as clicking a malicious link. The CVSS 3.1 base score is 2.5, reflecting low severity due to the attack vector being adjacent network (AV:A), high attack complexity (AC:H), no privileges required (PR:N), and requiring user interaction (UI:R). The impact is limited to integrity (I:L) with no confidentiality or availability impact. No known exploits have been reported in the wild as of the publication date. The vulnerability could be leveraged in phishing campaigns or social engineering attacks to redirect users to malicious sites, potentially leading to credential theft or malware infection. Fortinet devices are widely deployed in enterprise and service provider networks, making this vulnerability relevant for organizations relying on these products for network security and access control.

For European organizations, the primary impact of CVE-2025-47890 is the potential facilitation of phishing or social engineering attacks through malicious URL redirection. While the vulnerability itself does not allow direct compromise of system confidentiality, integrity, or availability, it can be abused to redirect users to attacker-controlled sites that may host malware or credential harvesting pages. This risk is particularly relevant for organizations with large user bases accessing Fortinet portals or VPN gateways, where trust in URLs is critical. The low severity score indicates limited direct technical impact, but the indirect risk to user security and organizational reputation exists. Critical infrastructure sectors, government agencies, and enterprises with high reliance on Fortinet products for secure remote access could face increased exposure if attackers combine this vulnerability with other social engineering tactics. The absence of known exploits reduces immediate risk but does not eliminate the need for vigilance.

1. Monitor Fortinet's official advisories and apply patches or firmware updates as soon as they become available for the affected FortiOS, FortiProxy, and FortiSASE versions. 2. Implement strict URL filtering and web proxy controls to detect and block suspicious redirects or external links originating from Fortinet portals. 3. Educate users about the risks of clicking on unexpected links, especially those received via email or messaging platforms, to reduce the likelihood of successful phishing attacks leveraging this vulnerability. 4. Configure Fortinet devices to minimize exposure of web interfaces to untrusted networks, restricting access to trusted IP ranges where possible. 5. Enable logging and alerting on redirect-related events to identify potential exploitation attempts early. 6. Conduct regular security assessments and penetration tests focusing on web redirection and access control mechanisms within Fortinet products. 7. Consider deploying multi-factor authentication (MFA) on portals to reduce the risk of credential compromise if users are redirected to malicious sites.