SB2023101192 - Multiple vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Buffer overflow (CVE-ID: CVE-2023-4966)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error. A remote non-authenticated attacker can send specially crafted data to the device, trigger memory corruption and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system but requires that the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or as AAAvirtualserver.

Note, the vulnerability is being actively exploited in the wild since August 2023.

2) Buffer overflow (CVE-ID: CVE-2023-4967)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a boundary error. A remote non-authenticated attacker can send specially crafted data to the device, trigger memory corruption and perform a denial of service (DoS) attack.

Successful exploitation of this vulnerability requires that the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or as AAAvirtualserver.

Remediation

Install update from vendor's website.

References

• https://support.citrix.com/article/CTX579459
• https://www.mandiant.com/resources/blog/remediation-netscaler-adc-gateway-cve-2023-4966