Citrix NetScaler memory disclosure via gateway config flaw
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Out-of-bounds read in Citrix NetScaler ADC/Gateway allows unauthenticated remote attackers to leak sensitive data including session tokens.
Citrix has released patches for multiple vulnerabilities affecting NetScaler ADC and NetScaler Gateway products. The most severe is CVE-2025-5777, an out-of-bounds read vulnerability in systems configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server. The flaw stems from insufficient input validation and allows a remote, unauthenticated attacker to trigger memory overreads on the affected interface, potentially disclosing sensitive data such as authenticated session tokens. Successful exploitation could lead to further unauthorized access to the appliance or connected systems.
A secondary vulnerability, CVE-2025-5349, is an improper access control flaw in the NetScaler Management Interface affecting versions 14.1 before 14.1-43.56 and 13.1 before 13.1-58.32. This allows unauthenticated actors with access to the management IP (NSIP, Cluster Management IP, or local GSLB Site IP) to interact with restricted management functions. There are currently no reports of either vulnerability being actively exploited in the wild. Defenders should prioritize patching affected versions immediately, particularly those with externally-exposed Gateway configurations.
Mentioned in this report
Source reporting: https://www.cisecurity.org/advisory/multiple-vulnerabilities-in-citrix-products-could-allow-for-disclosure-of-sensitive-data_2025-060
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