{"cveID":"CVE-2023-4966","vendorProject":"Citrix","product":"NetScaler ADC and NetScaler Gateway","vulnerabilityName":"Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability","dateAdded":"2023-10-18","shortDescription":"Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for sensitive information disclosure when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.","requiredAction":"Apply mitigations and kill all active and persistent sessions per vendor instructions [https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/] OR discontinue use of the product if mitigations are unavailable.","dueDate":"2023-11-08","knownRansomwareCampaignUse":"Known","notes":"https://www.netscaler.com/blog/news/cve-2023-4966-critical-security-update-now-available-for-netscaler-adc-and-netscaler-gateway/, https://support.citrix.com/article/CTX579459/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20234966-and-cve20234967 ;  https://nvd.nist.gov/vuln/detail/CVE-2023-4966","cwes":["CWE-119"],"year":2023,"state":"mapped","stale_reasons":[],"mappings":[{"domain":"enterprise","cve":"CVE-2023-4966","technique":"T1574","technique_name_at_mapping":"Hijack Execution Flow","mapping_type":"exploitation_technique","capability_group":"buffer_overflow","comments":"This is a buffer overflow vulnerability that results in unauthorized disclosure of memory, including session tokens.  ","references":["https://www.assetnote.io/resources/research/citrix-bleed-leaking-session-tokens-with-cve-2023-4966","https://www.cisa.gov/guidance-addressing-citrix-netscaler-adc-and-gateway-vulnerability-cve-2023-4966-citrix-bleed"],"status":"complete","source_file":"kev-07.28.2025_attack-16.1-enterprise.json","attack_version":"16.1","kev_snapshot":"07/28/2025"},{"domain":"enterprise","cve":"CVE-2023-4966","technique":"T1005","technique_name_at_mapping":"Data from Local System","mapping_type":"primary_impact","capability_group":"buffer_overflow","comments":"This is a buffer overflow vulnerability that results in unauthorized disclosure of memory, including session tokens.","references":["https://www.assetnote.io/resources/research/citrix-bleed-leaking-session-tokens-with-cve-2023-4966","https://www.cisa.gov/guidance-addressing-citrix-netscaler-adc-and-gateway-vulnerability-cve-2023-4966-citrix-bleed"],"status":"complete","source_file":"kev-07.28.2025_attack-16.1-enterprise.json","attack_version":"16.1","kev_snapshot":"07/28/2025"},{"domain":"enterprise","cve":"CVE-2023-4966","technique":"T1134.001","technique_name_at_mapping":"Token Impersonation/Theft","mapping_type":"secondary_impact","capability_group":"buffer_overflow","comments":"This is a buffer overflow vulnerability that results in unauthorized disclosure of memory, including session tokens.","references":["https://www.assetnote.io/resources/research/citrix-bleed-leaking-session-tokens-with-cve-2023-4966","https://www.cisa.gov/guidance-addressing-citrix-netscaler-adc-and-gateway-vulnerability-cve-2023-4966-citrix-bleed"],"status":"complete","source_file":"kev-07.28.2025_attack-16.1-enterprise.json","attack_version":"16.1","kev_snapshot":"07/28/2025"}],"techniques":[{"id":"T1005","domains":["enterprise"],"in_current_bundle":true,"live":true,"name_now":"Data from Local System","name_at_mapping":"Data from Local System","renamed":false,"revoked_by":null,"mapping_types":["primary_impact"],"sigma_rule_count":14,"has_detection_strategy":true},{"id":"T1134.001","domains":["enterprise"],"in_current_bundle":true,"live":true,"name_now":"Token Impersonation/Theft","name_at_mapping":"Token Impersonation/Theft","renamed":false,"revoked_by":null,"mapping_types":["secondary_impact"],"sigma_rule_count":9,"has_detection_strategy":true},{"id":"T1574","domains":["enterprise"],"in_current_bundle":true,"live":true,"name_now":"Hijack Execution Flow","name_at_mapping":"Hijack Execution Flow","renamed":false,"revoked_by":null,"mapping_types":["exploitation_technique"],"sigma_rule_count":8,"has_detection_strategy":true}],"mapping_types":["exploitation_technique","primary_impact","secondary_impact"],"has_exploitation_technique":true,"mapping_attack_versions":["16.1"],"mapping_domains":["enterprise"],"sigma_coverage":"full","sigma_rules_tagged_cve":["87c83d8e-5390-44ce-aa4a-d3b37e54d0a0","a4e068b5-e27c-4f21-85b3-e69e5a4f7ce1","aee7681f-b53d-4594-a9de-ac51e6ad3362","ff349b81-617f-4af4-924f-dbe8ea9bab41"],"added_after_mapping_snapshot":false,"_source":"kevmap","_built":"2026-08-23 05:47 UTC","_attack_version":"19.2"}