Zero-day vulnerability in Citrix Netscaler ADC

Code Injection
CVE-2023-3519

Vulnerability details

Advisory: SB2023071927 - Multiple vulnerabilities in Citrix NetScaler ADC and NetScaler Gateway

Vulnerable component: Citrix Netscaler ADC

CVE-ID: CVE-2023-3519

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

CWE-ID: CWE-94 - Improper Control of Generation of Code ('Code Injection')

Description:

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

The vulnerability exists due to improper input validation when the appliance is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAAтАпvirtualтАпserver. A remote non-authenticated attacker can send a specially crafted request and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note, the vulnerability is being actively exploited in the wild.

External links:

https://support.citrix.com/article/CTX561482/citrix-adc-and-citrix-gateway-security-bulletin-for-cve20233519-cve20233466-cve20233467

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.