Citrix NetScaler ADC and Gateway Out-of-Bounds Read Vulnerability

Critical Threat Advisory: This vulnerability is documented in active Ransomware campaigns. Immediate remediation required.

Technical Severity

CVSS v3.1 Metrics

HIGH

7.5 / 10

Minimal Risk Critical

Vector Specification

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Exploitation Likelihood

EPSS Prediction

77.55 %

Predictive Probability

Percentile Rank

99.0 th

Documented as more likely to be exploited than 99.0% of known CVEs.

Detection Date

Jul 10, 2025

Remediation Due

Jul 11, 2025

CISA Catalog Active

Threat Analysis

Citrix NetScaler ADC and Gateway contain an out-of-bounds read vulnerability due to insufficient input validation. This vulnerability can lead to memory overread when the NetScaler is configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) OR AAA virtual server.

Remediation Directive

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Asset Context

Vendor Identity

Citrix

Affected Product

NetScaler ADC and Gateway

Ransomware Status

Campaign Use Known

Weakness Classification

CWE-125

External Intelligence

https://support.citrix.com/support-home/kbsearch/article?articleNumber=CTX693420

NVD

National Vulnerability Database

https://nvd.nist.gov/vuln/detail/CVE-2025-5777