Buffer overflow in Citrix Netscaler ADC and Citrix NetScaler Gateway - CVE-2025-6543
Published: June 26, 2025
Vulnerability identifier: #VU111952
CSH Severity: High
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-6543
CWE-ID: CWE-119
Exploitation vector: Remote access
Exploit availability:
The vulnerability is being exploited in the wild
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a boundary error when handling incoming requests. A remote attacker can send specially crafted traffic to the server, trigger memory corruption and perform a denial of service (DoS) attack.
Successful exploitation of the vulnerability requires that NetScaler is configured as Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.
Note, the vulnerability is being actively exploited in the wild.
Affected software
Citrix Netscaler ADC
Citrix NetScaler Gateway
Citrix NetScaler Gateway
How to mitigate CVE-2025-6543
Install updates from vendor's website.
Citrix Netscaler ADC - addressed in versions 13.1-59.19, 14.1-47.46
Citrix NetScaler Gateway - addressed in versions 13.1-59.19, 14.1-47.46
Citrix NetScaler Gateway - addressed in versions 13.1-59.19, 14.1-47.46