CVE-2019-5591 Scanner

FortiGate is a network security solution developed by Fortinet, used by enterprises for firewall, VPN, and traffic management. Fortinet's solutions are highly scalable, catering to the needs of small to large organizations, and include features such as intrusion prevention, web filtering, and deep packet inspection. The product has a reputation for being secure and reliable, often deployed in environments where network security is paramount. FortiOS, the operating system of FortiGate, offers a range of security and networking functionalities. Users include governments, educational institutions, and businesses needing robust security posture. FortiGate solutions work on both physical appliances and virtual machines, ensuring flexibility in deployment.

The vulnerability in question is related to insecure LDAP configuration in FortiGate, which can lead to Man in the Middle (MitM) attacks. Specifically, inadequate settings such as missing CA certificates and lack of server identity checks make the LDAP communications susceptible to interception. The vulnerability allows unauthenticated attackers within the same subnet to impersonate legitimate LDAP servers. Without proper configuration, sensitive information like credentials can be exposed to third parties. It's a medium severity vulnerability with significant potential impacts if exploited. Properly securing LDAP settings is critical to prevent these issues.

The vulnerability occurs in FortiGate due to missing security checks in its LDAP configuration. Important elements such as secure LDAPS and CA-certificate configurations are not enforced by default, leaving room for attackers. The /login' and /logincheck' endpoints on FortiGate devices are involved, and they need robust checks to avoid MitM scenarios. Attackers on the same network can craft responses that appear legitimate in order to capture sensitive data. Such vulnerability can be exploited via different protocols, such as DNS and HTTP, making it critical to apply necessary patches and configurations. Neglecting these configurations allows attackers to manipulate LDAP communications easily.

Exploiting this vulnerability could allow an attacker to intercept and manipulate data communicated with LDAP servers. This could lead to unauthorized access to sensitive information such as usernames and passwords. It's crucial as it may cause broad consequences, including unauthorized network access, data leakage, and raising additional security concerns like full network compromise. The information gathered could be used for further attacks within the organizational network, breaching confidentiality. Moreover, trust in network security operations could be severely undermined, affecting the institution's credibility.

REFERENCES

• https://github.com/ayewo/fortios-ldap-mitm-poc-CVE-2019-5591
• https://www.fortiguard.com/psirt/FG-IR-19-037