Cisco DNA Center Certificate Validation Vulnerability

Vulnerability

The vulnerability resides in the Cisco Identity Services Engine (ISE) integration feature of Cisco DNA Center Software. An incomplete validation of the X.509 certificate used when establishing a connection between DNA Center and an ISE server allows an unauthenticated remote attacker to supply a crafted certificate and intercept communications [1]. The exact affected versions are those prior to the fixed release; the specific version numbers are disclosed in the Cisco Security Advisory [1].

Exploitation

An attacker must be in a network position capable of performing a man-in-the-middle attack on the ISE-to-DNA Center connection. No authentication is required. The attacker supplies a crafted X.509 certificate during the TLS handshake; because DNA Center does not fully validate the certificate, the attacker can successfully impersonate the ISE server and intercept the traffic [1].

Impact

Successful exploitation allows the attacker to view and alter sensitive information that the ISE server maintains about clients connected to the network. This includes both disclosure of confidential data and the ability to modify it, potentially leading to further compromise of network operations [1].

Mitigation

Cisco has released free software updates that fix the certificate validation issue [1]. Customers should upgrade to the fixed version indicated in the Cisco Security Advisory. No workarounds are mentioned, and the vulnerability is not listed on the CISA Known Exploited Vulnerabilities (KEV) catalog as of the publication date. The advisory provides instructions for obtaining the update through Cisco TAC for customers without service contracts [1].