{"id":"CVE-2018-13383","published":"2019-05-29T18:29:00Z","modified":"2026-06-17T01:39:18Z","title":"Fortinet FortiOS and FortiProxy Out-of-bounds Write","vendor":"Fortinet","product":"FortiOS and FortiProxy","tier":"core","eol":null,"description":{"text":"A heap buffer overflow in Fortinet FortiOS 6.0.0 through 6.0.4, 5.6.0 through 5.6.10, 5.4.0 through 5.4.12, 5.2.14 and earlier and FortiProxy 2.0.0, 1.2.8 and earlier in the SSL VPN web portal may cause the SSL VPN web service termination for logged in users due to a failure to properly handle javascript href data when proxying webpages.","provenance":"source","from":"NVD"},"summary":{"text":"Fortinet FortiOS and FortiProxy contain an out-of-bounds write (heap buffer overflow) in the SSL VPN web portal, where javascript href data is mishandled while proxying webpages. An unauthenticated remote attacker can trigger it over the network, but it requires user interaction, and a logged-in user's SSL VPN web service is terminated.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:06:57Z"},"cvss":{"score":6.5,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.32473,"percentile":0.9833,"date":"2026-10-28","provenance":"source"},"kev":{"dateAdded":"2022-01-10","dueDate":"2022-07-10","ransomware":true,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2018-13383","provenance":"source"},"vulncheckKev":{"dateAdded":"2019-10-02","exploitedFirstSeen":"2019-10-02","ransomware":true,"evidence":[{"url":"https://www.ncsc.gov.uk/news/alert-vpn-vulnerabilities","date":"2019-10-02"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2022-01-10"}],"evidenceTotal":2,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"}],"references":[{"url":"https://fortiguard.com/advisory/FG-IR-18-388","tags":["Mitigation","Vendor Advisory"]},{"url":"https://fortiguard.com/advisory/FG-IR-20-229","tags":["Vendor Advisory"]},{"url":"https://fortiguard.com/advisory/FG-IR-18-388","tags":["Mitigation","Vendor Advisory"]},{"url":"https://fortiguard.com/advisory/FG-IR-20-229","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-13383","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: remote exploitation of internet-facing SSL VPN web portal","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"in the SSL VPN web portal may cause the SSL VPN web service termination","start":167,"end":238}],"model":"claude-haiku-5-5","confidence":"low","confidenceNote":"needs user interaction; not a public-facing exploit"},{"id":"T1499.004","name":"Application or System Exploitation","tactics":["impact"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: service crash disrupts VPN availability for users","mappingType":"primary_impact","evidence":[{"from":"description","quote":"may cause the SSL VPN web service termination for logged in users","start":193,"end":258}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2018-5327","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2018-5327","exploited":true,"exploitedSince":"2022-01-10","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"primary","techniques":["T1499.004"],"provenance":"ai"},{"stage":"related","techniques":["T1190"],"provenance":"ai","lowConfidence":true}],"timeline":[{"date":"2019-05-29","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-13383","provenance":"source"},{"date":"2019-10-02","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://www.ncsc.gov.uk/news/alert-vpn-vulnerabilities","provenance":"source"},{"date":"2022-01-10","kind":"kev","label":"Added to CISA KEV (known ransomware use)","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2022-01-10","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2018-5327","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":957},"priority":{"score":72.2,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 2584 days ago"},{"name":"Known ransomware use","points":10.0,"detail":"CISA KEV and VulnCheck KEV: Known"},{"name":"EPSS percentile","points":19.67,"detail":"percentile 0.9833"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":4.55,"detail":"base score 6.5"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}