External risk intelligence

Citrix ADC and Gateway Unauthorized Access Vulnerability

CVE advisoryKnown Exploit

CVE-2020-8193

Certain Citrix network appliances have an access control vulnerability that allows unauthorized access to some URL endpoints. This could lead to unauthorized data exposure or modification, posing a risk to business operations.

5Halo Surface Signal

Authentication Bypass

Citrix Application Delivery Controller Firmware

10.5 to before 10.5-70.1811.1 to before 11.1-64.1412.0 to before 12.0-63.2112.1 to before 12.1-57.1813.0 to before 13.0-58.3010.2 to before 10.2.711.0 to before 11.0.3d11.1 to before...

External exposure likelihood

Halo Surface Signal score for CVE-2020-8193

This vulnerability affects Citrix ADC and Gateway, which are edge network appliances typically deployed as internet-facing gateways for remote access and traffic management. These products are designed to be public-facing, serving as the primary entry point into an organization's network, making them highly likely to be reachable from the internet.

Horizon Alert

Summary of the vulnerability and why it matters

Certain versions of Citrix Application Delivery Controller, Gateway, and SD-WAN WANOP appliances are susceptible to an improper access control vulnerability. This flaw allows unauthorized access to specific URL endpoints on these systems. This could potentially lead to unauthorized disclosure or modification of sensitive information, impacting data integrity and confidentiality.

Vulnerable Citrix network appliances
Flaw permits unauthenticated access
Business risk of data exposure

Attack Path

How an attacker could exploit the issue

This vulnerability allows unauthenticated access to specific URL endpoints within Citrix ADC and Citrix Gateway. An attacker must first have network access to the NetScaler IP. The attacker can then trigger the vulnerability by accessing these endpoints, potentially leading to unauthorized information disclosure or modification.

Exposure via network access to NetScaler IP.
Attacker accesses specific URL endpoints.
Leads to unauthorized access to data.

Live Threat

Current exploitation, exposure, and threat context

This vulnerability allows unauthenticated access to certain network endpoints within Citrix ADC and Citrix Gateway. Exploitation requires an attacker to have network access to the NetScaler IP address. The potential impact includes unauthorized access to sensitive information or system functionality, posing a risk to business operations.

Attackers with network access.
Requires network access to NetScaler IP.
Potential for unauthorized access.

Priority actions

Operational Fix

Recommended remediation, mitigation, and detection steps

An improper access control vulnerability in Citrix ADC, Citrix Gateway, and Citrix SD-WAN WAN-OP appliances allows unauthenticated access to specific URL endpoints. This could enable attackers to gain unauthorized access to certain functions or data within the affected systems. Addressing this issue requires identifying and securing all instances of the vulnerable products.

Find exposed Citrix assets.
Limit access to these systems.
Update, verify, and monitor.

Frequently asked questions

What are Citrix ADC and Citrix Gateway?

Citrix ADC and Citrix Gateway are network appliances that manage and secure application traffic, providing secure remote access. They function as a primary entry point for many business applications and services.

What weakness does CVE-2020-8193 reveal?

CVE-2020-8193 is an improper access control vulnerability (CWE-284). This weakness means the system does not correctly verify user permissions, allowing unauthenticated attackers to access specific URL endpoints.

How can an attacker exploit this flaw?

An attacker with network access to the NetScaler IP can exploit this flaw by accessing specific URL endpoints. This bypasses access controls, potentially leading to unauthorized data access or system function alteration.

What is the relevance of CVE-2020-8193 to security?

This vulnerability affects internet-facing Citrix appliances, making them a likely target. Exploitation can lead to unauthorized access, impacting data confidentiality and integrity.

What steps should be taken to respond to this vulnerability?

Organizations should identify all vulnerable Citrix ADC, Gateway, and SD-WAN WANOP appliances. Applying vendor-provided updates and verifying system security are crucial steps to mitigate this risk.

References

Written by Nicholas Merritt

External-surface CVE analysis and Halo Surface Signal prioritization for Halo Threat Intelligence.