{"schema":"threatline.record/2","record":{"id":"CVE-2023-6549","aliases":[],"summary":"Citrix NetScaler ADC and NetScaler Gateway Buffer Overflow Vulnerability","details":"Citrix NetScaler ADC and NetScaler Gateway contain a buffer overflow vulnerability that allows for a denial-of-service when configured as a Gateway (VPN virtual server, ICA Proxy, CVPN, RDP Proxy) or AAA virtual server.","categories":["Network & edge"],"product":"NetScaler ADC and NetScaler Gateway","vendor":"Citrix","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","source_modified_at":"2025-10-21T23:05:27.936Z","fetched_at":"2026-10-23T18:42:43.628194Z","product":"NetScaler ADC","vendor":"Cloud Software Group","versions":[{"lessThan":"12.35","status":"affected","version":"14.1","versionType":"patch"},{"lessThan":"51.15","status":"affected","version":"13.1","versionType":"patch"},{"lessThan":"92.21","status":"affected","version":"13.0","versionType":"patch"},{"lessThan":"37.176","status":"affected","version":"13.1-FIPS","versionType":"patch"},{"lessThan":"55.302","status":"affected","version":"12.1-FIPS","versionType":"patch"},{"lessThan":"55.302","status":"affected","version":"12.1-NDcPP","versionType":"patch"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","source_modified_at":"2025-10-21T23:05:27.936Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"NetScaler ADC","ecosystem":null},"version":"12.35","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","source_modified_at":"2025-10-21T23:05:27.936Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"NetScaler ADC","ecosystem":null},"version":"51.15","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","source_modified_at":"2025-10-21T23:05:27.936Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"NetScaler ADC","ecosystem":null},"version":"92.21","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","source_modified_at":"2025-10-21T23:05:27.936Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"NetScaler ADC","ecosystem":null},"version":"37.176","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","source_modified_at":"2025-10-21T23:05:27.936Z","fetched_at":"2026-10-23T18:42:43.628194Z","package":{"name":"NetScaler ADC","ecosystem":null},"version":"55.302","basis":"first unaffected version stated in the CVE record"}],"cvss":8.2,"severity":"High","kev":{"listed":true,"date_added":"2024-01-17","due_date":"2024-02-07","required_action":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","ransomware_campaign_use":"Unknown"},"epss":{"probability":0.57633,"percentile":0.99086,"score_date":"2026-10-23"},"published_at":"2024-01-17T20:15:53.345Z","modified_at":"2025-10-21T23:05:27.936Z","provenance":[{"source":"CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23T17:00:09.9001Z"},{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2023-6549","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2025-10-21T23:05:27.936Z"},{"source":"Nuclei","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-6549.yaml","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":null},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2023-6549","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CISA KEV","CVE List","Nuclei","EPSS"],"references":[{"source":"CVE List","url":"https://support.citrix.com/article/CTX584986/netscaler-adc-and-netscaler-gateway-security-bulletin-for-cve20236548-and-cve20236549","tags":["x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-6549","source":"CISA KEV"},{"source":"CVE List","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-6549","tags":["government-resource"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"active","automatable":"yes","technical_impact":"partial","assessed_at":"2024-01-31T05:00:20.477654Z"},"exploits":[{"source":"Nuclei","kind":"Scanner template","name":"Citrix Netscaler ADC & Gateway - 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