Zero-day vulnerability in Citrix NetScaler Gateway

Buffer overflow
CVE-2023-4966

Vulnerability details

Advisory: SB2023101192 - Multiple vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway

Vulnerable component: Citrix NetScaler Gateway

CVE-ID: CVE-2023-4966

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L/E:H/RL:O/RC:C

CWE-ID: CWE-119 - Memory corruption

Description:

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.

External links:



About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.