CVE-2020-8195

What is Citrix ADC?

Citrix ADC (formerly NetScaler) and Citrix Gateway are application delivery controllers and remote-access gateways deployed at the network edge of organizations to load-balance application traffic and broker secure remote access. Given their perimeter position, information disclosure bugs in these appliances are especially valuable to attackers doing reconnaissance ahead of a larger intrusion.

Overview

CVE-2020-8195 is an information disclosure vulnerability in Citrix ADC, Citrix Gateway, and certain SD-WAN WANOP appliance models. A low-privileged authenticated user can access sensitive information they should not be entitled to view, such as internal configuration details that could aid further attacks against the appliance or the network behind it. It was disclosed alongside CVE-2020-8193 and CVE-2020-8196 as part of the same July 2020 Citrix security bulletin addressing several related issues in the same product family.

Technical Details

The flaw (CWE-20, Improper Input Validation) allows a low-privileged user to retrieve data that should be restricted to higher-privilege roles, due to insufficient checks on what a given request is permitted to return. The CVSS vector (PR:L, C:H) indicates that while some level of authentication is required, the confidentiality impact is high — meaning the exposed data is significant enough to matter for follow-on attacks, such as configuration secrets or internal network details.

Discovery

Disclosed and patched by Citrix as part of its July 2020 security bulletin, identified through Citrix's own security review process following heightened scrutiny of the ADC/Gateway product line after the earlier CVE-2019-19781 incident.

Exploitation Context

CISA's KEV catalog listing confirms this vulnerability has been exploited in the wild. Information disclosure bugs on perimeter appliances like Citrix ADC are frequently used as a reconnaissance or escalation step by attackers who have already obtained low-privileged access, helping them map internal configuration before pursuing a more impactful follow-on attack.

Remediation

1. Apply the Citrix-patched firmware/software release addressing this vulnerability across all affected ADC, Gateway, and SD-WAN WANOP appliances.
2. Review and tighten role-based access controls on the appliance to minimize what low-privileged accounts can query.
3. Rotate any credentials or configuration secrets that may have been exposed to lower-privileged users prior to patching.
4. Monitor appliance access logs for unusual data-retrieval requests from non-administrative accounts.
5. Restrict management interface access to trusted networks only, reducing the pool of users who could exploit this even at low privilege.