# Citrix Bleed (CVE-2023-4966) Citrix Bleed, which the vendor scored 9.4 and the NVD 7.5; the Deepinfo score follows the NVD. Source: https://docs.deepinfo.com/reference/vulnerability/detail/examples/cve-2023-4966/ Last updated: 2026-09-24 --- `GET https://api.deepinfo.com/v1/discovery/vulnerability-detail?cve=CVE-2023-4966` Citrix Bleed, which the vendor scored 9.4 and the NVD 7.5; the Deepinfo score follows the NVD. Example 5 of 7 in **Well-Known CVEs** · [Vulnerability Detail Examples](/reference/vulnerability/detail/examples/) · endpoint: [Detail](/reference/vulnerability/detail/) Tags: `param` `cve` · `value` `CVE-2023-4966` Asks for `CVE-2023-4966`, the NetScaler ADC and Gateway session token leak. ## What to Notice - `metrics.cvss_metric_v31` has two scores for the same version: 9.4 (`Secondary`, from Citrix) and 7.5 (`Primary`, from the NVD). - `enrichment.vdeep_metric` uses the `Primary` 7.5. - `enrichment.cisa_kev.known_ransomware_campaign_use` is `Known`. ## Request | Parameter | In | Value | |---|---|---| | `cve` | query | `CVE-2023-4966` | ```bash curl 'https://api.deepinfo.com/v1/discovery/vulnerability-detail?cve=CVE-2023-4966' \ -H 'apikey: YOUR_API_KEY' \ -H 'Accept: application/json' ``` ## Response ### 200 · OK > Shortened for this page: enrichment.cwe[].capec_id: first 10 items `Content-Type: application/json` · `ratelimit-limit: 1` · `ratelimit-remaining: 0` · `ratelimit-reset: 1` · `x-ratelimit-limit-second: 1` · `x-ratelimit-remaining-second: 0` · `deepinfo-request-id: 5f0c6a8e-1b2d-4c3e-9f4a-7b8c9d0e1f2a` ```json { "id": "CVE-2023-4966", "source_identifier": "user@citrix.com", "published": "2023-10-10T14:15:10Z", "last_modified": "2026-07-31T04:16:44Z", "status": "Analyzed", "evaluator_comment": null, "evaluator_solution": null, "evaluator_impact": null, "cisa_exploit_add": "2023-10-18", "cisa_action_due": "2023-11-08", "cisa_required_action": "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.", "cisa_vulnerability_name": "Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability", "descriptions": [ { "lang": "en", "value": "Sensitive information disclosure in NetScaler ADC and NetScaler Gateway when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA  virtual server." }, { "lang": "es", "value": "Divulgación de información confidencial en NetScaler ADC y NetScaler Gateway cuando se configura como Gateway (servidor virtual VPN, ICA Proxy, CVPN, RDP Proxy) o servidor \"virtual\" AAA." } ], "references": [ { "url": "http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html", "source": "user@citrix.com", "tags": [ "Third Party Advisory", "VDB Entry" ] }, { "url": "https://support.citrix.com/article/CTX579459", "source": "user@citrix.com", "tags": [ "Vendor Advisory" ] }, { "url": "http://packetstormsecurity.com/files/175323/Citrix-Bleed-Session-Token-Leakage-Proof-Of-Concept.html", "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": [ "Third Party Advisory", "VDB Entry" ] }, { "url": "https://support.citrix.com/article/CTX579459", "source": "af854a3a-2127-422b-91ae-364da2661108", "tags": [ "Vendor Advisory" ] }, { "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-4966", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": [ "US Government Resource" ] } ], "metrics": { "cvss_metric_v40": null, "cvss_metric_v31": [ { "source": "user@citrix.com", "type": "Secondary", "cvss_data": { "version": "3.1", "vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L", "attack_vector": "NETWORK", "attack_complexity": "LOW", "privileges_required": "NONE", "user_interaction": "NONE", "scope": "UNCHANGED", "confidentiality_impact": "HIGH", "integrity_impact": "HIGH", "availability_impact": "LOW", "base_score": 9.4, "base_severity": "CRITICAL", "exploit_code_maturity": null, "remediation_level": null, "report_confidence": null, "temporal_score": null, "temporal_severity": null, "confidentiality_requirement": null, "integrity_requirement": null, "availability_requirement": null, "modified_attack_vector": null, "modified_attack_complexity": null, "modified_privileges_required": null, "modified_user_interaction": null, "modified_scope": null, "modified_confidentiality_impact": null, "modified_integrity_impact": null, "modified_availability_impact": null, "environmental_score": null, "environmental_severity": null }, "exploitability_score": 3.9, "impact_score": 5.5 }, { "source": "user@nist.gov", "type": "Primary", "cvss_data": { "version": "3.1", "vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "attack_vector": "NETWORK", "attack_complexity": "LOW", "privileges_required": "NONE", "user_interaction": "NONE", "scope": "UNCHANGED", "confidentiality_impact": "HIGH", "integrity_impact": "NONE", "availability_impact": "NONE", "base_score": 7.5, "base_severity": "HIGH", "exploit_code_maturity": null, "remediation_level": null, "report_confidence": null, "temporal_score": null, "temporal_severity": null, "confidentiality_requirement": null, "integrity_requirement": null, "availability_requirement": null, "modified_attack_vector": null, "modified_attack_complexity": null, "modified_privileges_required": null, "modified_user_interaction": null, "modified_scope": null, "modified_confidentiality_impact": null, "modified_integrity_impact": null, "modified_availability_impact": null, "environmental_score": null, "environmental_severity": null }, "exploitability_score": 3.9, "impact_score": 3.6 } ], "cvss_metric_v30": null, "cvss_metric_v2": null }, "weaknesses": [ { "source": "user@citrix.com", "type": "Secondary", "description": [ { "lang": "en", "value": "CWE-119" } ] }, { "source": "user@nist.gov", "type": "Primary", "description": [ { "lang": "en", "value": "NVD-CWE-noinfo" } ] } ], "configurations": [ { "operator": null, "negate": null, "nodes": [ { "operator": "OR", "negate": false, "cpe_match": [ { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*", "match_criteria_id": "492BEB4B-7A4B-47C2-93D1-2B0683AA3A20", "version_start_including": "12.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "12.1-55.300" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*", "match_criteria_id": "81EF12C2-4197-4C0D-BE11-556F05DAD646", "version_start_including": "12.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "12.1-55.300" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*", "match_criteria_id": "9EEC53B2-686A-4C6F-98DE-5D6AE804B0A8", "version_start_including": "13.0", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.0-92.19" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*", "match_criteria_id": "109301A8-9ADD-4A49-9C45-D21A4DA840E9", "version_start_including": "13.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.1-37.164" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*", "match_criteria_id": "5C1739C5-48C1-46BC-A524-B4CC4C5B6436", "version_start_including": "13.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.1-49.15" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*", "match_criteria_id": "9148C36D-98B4-4166-8B9A-449EA86BA4B1", "version_start_including": "14.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "14.1-8.50" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*", "match_criteria_id": "5FB1412D-F8D8-4592-A8A9-C1B841B93D5E", "version_start_including": "13.0", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.0-92.19" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*", "match_criteria_id": "28A08B32-D145-499F-866E-BEEEDEBB2901", "version_start_including": "13.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.1-49.15" }, { "vulnerable": true, "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*", "match_criteria_id": "4F1610E6-FE48-4339-8E74-765E0517E33D", "version_start_including": "14.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "14.1-8.50" } ] } ] } ], "vendor_comments": null, "enrichment": { "cpe": [ { "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*", "vendor": "citrix", "product": "netscaler_application_delivery_controller", "product_type": "a", "vulnerable": true, "version_start_including": "12.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "12.1-55.300", "affected_versions_first": "12.1-55.297", "affected_versions_last": "12.1", "affected_versions": [ "12.1-55.297", "12.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:12.1:*:*:*:fips:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:12.1-55.297:*:*:*:fips:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:ndcpp:*:*:*", "vendor": "citrix", "product": "netscaler_application_delivery_controller", "product_type": "a", "vulnerable": true, "version_start_including": "12.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "12.1-55.300", "affected_versions_first": "12.1-55.297", "affected_versions_last": "12.1", "affected_versions": [ "12.1-55.297", "12.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:12.1:*:*:*:ndcpp:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:12.1-55.297:*:*:*:ndcpp:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*", "vendor": "citrix", "product": "netscaler_application_delivery_controller", "product_type": "a", "vulnerable": true, "version_start_including": "13.0", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.0-92.19", "affected_versions_first": "13.0-91.13", "affected_versions_last": "13.0", "affected_versions": [ "13.0-91.13", "13.0" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:13.0:*:*:*:-:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:13.0-91.13:*:*:*:-:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:fips:*:*:*", "vendor": "citrix", "product": "netscaler_application_delivery_controller", "product_type": "a", "vulnerable": true, "version_start_including": "13.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.1-37.164", "affected_versions_first": "13.1-37.159", "affected_versions_last": "13.1", "affected_versions": [ "13.1-37.159", "13.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:13.1:*:*:*:fips:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:13.1-37.159:*:*:*:fips:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*", "vendor": "citrix", "product": "netscaler_application_delivery_controller", "product_type": "a", "vulnerable": true, "version_start_including": "13.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.1-49.15", "affected_versions_first": "13.1-49.13", "affected_versions_last": "13.1", "affected_versions": [ "13.1-49.13", "13.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:13.1:*:*:*:-:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:13.1-49.13:*:*:*:-:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:*:*:*:*:-:*:*:*", "vendor": "citrix", "product": "netscaler_application_delivery_controller", "product_type": "a", "vulnerable": true, "version_start_including": "14.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "14.1-8.50", "affected_versions_first": "14.1", "affected_versions_last": "14.1", "affected_versions": [ "14.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_application_delivery_controller:14.1:*:*:*:-:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*", "vendor": "citrix", "product": "netscaler_gateway", "product_type": "a", "vulnerable": true, "version_start_including": "13.0", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.0-92.19", "affected_versions_first": "13.0-91.13", "affected_versions_last": "13.0", "affected_versions": [ "13.0-91.13", "13.0" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_gateway:13.0:*:*:*:*:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_gateway:13.0-91.13:*:*:*:*:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*", "vendor": "citrix", "product": "netscaler_gateway", "product_type": "a", "vulnerable": true, "version_start_including": "13.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "13.1-49.15", "affected_versions_first": "13.1-49.13", "affected_versions_last": "13.1", "affected_versions": [ "13.1-49.13", "13.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_gateway:13.1:*:*:*:*:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_gateway:13.1-49.13:*:*:*:*:*:*:*", "deprecated": false } ] }, { "criteria": "cpe:2.3:a:citrix:netscaler_gateway:*:*:*:*:*:*:*:*", "vendor": "citrix", "product": "netscaler_gateway", "product_type": "a", "vulnerable": true, "version_start_including": "14.1", "version_start_excluding": null, "version_end_including": null, "version_end_excluding": "14.1-8.50", "affected_versions_first": "14.1-4.42", "affected_versions_last": "14.1", "affected_versions": [ "14.1-4.42", "14.1" ], "cpe_names": [ { "cpe_name": "cpe:2.3:a:citrix:netscaler_gateway:14.1:*:*:*:*:*:*:*", "deprecated": false }, { "cpe_name": "cpe:2.3:a:citrix:netscaler_gateway:14.1-4.42:*:*:*:*:*:*:*", "deprecated": false } ] } ], "cwe": [ { "id": 119, "owasptop10_2021": null, "name": "Improper Restriction of Operations within the Bounds of a Memory Buffer", "description": "The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.", "capec_id": [ 8, 9, 10, 14, 24, 42, 44, 45, 46, 47 ], "scope": [ "Availability", "Confidentiality", "Integrity" ], "impact": [ "DoS: Crash, Exit, or Restart", "DoS: Resource Consumption (CPU)", "DoS: Resource Consumption (Memory)", "Execute Unauthorized Code or Commands", "Modify Memory", "Read Memory" ], "detection_method": [ "Architecture or Design Review", "Automated Dynamic Analysis", "Automated Static Analysis", "Automated Static Analysis - Binary or Bytecode", "Automated Static Analysis - Source Code", "Dynamic Analysis with Automated Results Interpretation", "Dynamic Analysis with Manual Results Interpretation", "Manual Static Analysis - Binary or Bytecode", "Manual Static Analysis - Source Code" ] } ], "epss_score": { "epss": 0.99999, "percentile": 0.99998, "date": "2026-09-23" }, "cisa_kev": { "vendor_project": "Citrix", "product": "NetScaler ADC and NetScaler Gateway", "vulnerability_name": "Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability", "date_added": "2023-10-18", "short_description": "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.", "required_action": "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.", "due_date": "2023-11-08", "known_ransomware_campaign_use": "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" }, "vdeep_metric": { "available_versions": [ "3.1" ], "source": "user@nist.gov", "type": "Primary", "cvss_data": { "version": "3.1", "vector_string": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N", "attack_vector": "NETWORK", "attack_complexity": "LOW", "attack_requirements": null, "privileges_required": "NONE", "user_interaction": "NONE", "vulnerable_system_confidentiality": "HIGH", "vulnerable_system_integrity": "NONE", "vulnerable_system_availability": "NONE", "subsequent_system_confidentiality": null, "subsequent_system_integrity": null, "subsequent_system_availability": null, "exploit_maturity": null, "confidentiality_requirements": null, "integrity_requirements": null, "availability_requirements": null, "modified_attack_vector": null, "modified_attack_complexity": null, "modified_attack_requirements": null, "modified_privileges_required": null, "modified_user_interaction": null, "modified_vulnerable_system_confidentiality": null, "modified_vulnerable_system_integrity": null, "modified_vulnerable_system_availability": null, "modified_subsequent_system_confidentiality": null, "modified_subsequent_system_integrity": null, "modified_subsequent_system_availability": null, "safety": null, "automatable": null, "recovery": null, "value_density": null, "vulnerability_response_effort": null, "provider_urgency": null, "base_score": 7.5, "base_severity": "HIGH" } } } } ``` ## Related Examples - [Log4Shell (CVE-2021-44228)](/reference/vulnerability/detail/examples/cve-2021-44228/) - [XZ Utils Backdoor (CVE-2024-3094)](/reference/vulnerability/detail/examples/cve-2024-3094/) - [EternalBlue (CVE-2017-0144)](/reference/vulnerability/detail/examples/cve-2017-0144/) - [OpenSSH regreSSHion (CVE-2024-6387)](/reference/vulnerability/detail/examples/cve-2024-6387/) - [Shellshock (CVE-2014-6271)](/reference/vulnerability/detail/examples/cve-2014-6271/) - [Heartbleed (CVE-2014-0160)](/reference/vulnerability/detail/examples/cve-2014-0160/)