{"id":"CVE-2018-0296","kind":"vulnerability","aliases":["CVE-2018-0296"],"related":[],"title":"Cisco Adaptive Security Appliance (ASA): Cisco Adaptive Security Appliance (ASA) Denial-of-Service Vulnerability","description":"A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. It is also possible on certain software releases that the ASA will not reload, but an attacker could view sensitive system information without authentication by using directory traversal techniques. The vulnerability is due to lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition or unauthenticated disclosure of information. This vulnerability applies to IPv4 and IPv6 HTTP traffic. This vulnerability affects Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 1000V Cloud Firewall, ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCvi16029.","summary":"Cisco ASA firewalls have an input validation flaw in how they handle crafted HTTP URLs. An unauthenticated remote attacker can crash the device or read some information from it.","severity":"high","cvss":7.5,"epss":0.99908,"exploited":true,"exploited_at":"2021-11-03T00:00:00+00:00","products":[{"name":"Cisco Adaptive Security Appliance (ASA)","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["asa","cisco","exploited","firewall","infrastructure","self-hosted"],"not_affected_if":["default-config"],"how_to_check":null,"fix":"Apply the Cisco ASA update that addresses CVE-2018-0296, per Cisco's vendor advisory. Fixed version numbers are not in the sources.","status":"open","published_at":"2018-06-07T12:29:00+00:00","first_seen_at":"2026-10-23T19:11:53+00:00","triaged_at":"2026-10-23T21:33:40+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:33:40Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Cisco ASA update that addresses CVE-2018-0296, per Cisco's vendor advisory. Fixed version numbers are not in the sources.","reach":"internet","impact":"medium","summary":"Cisco ASA firewalls have an input validation flaw in how they handle crafted HTTP URLs. An unauthenticated remote attacker can crash the device or read some information from it.","category":"infrastructure","who_cares":["cisco","asa","firewall","self-hosted"],"confidence":0.6,"needs_auth":"no","worst_case":"Device denial of service and some information disclosure from the appliance","analyst_note":"Find the Cisco advisory for CVE-2018-0296 to get affected and fixed ASA versions and any HTTP-server feature prerequisites; KEV lists it as exploited, so confirm the exact impact.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["default-config"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000472,"input_tokens":2891,"output_tokens":366,"severity_before":"unknown"},"analyst_status":"queued","analyst_note":"Find the Cisco advisory for CVE-2018-0296 to get affected and fixed ASA versions and any HTTP-server feature prerequisites; KEV lists it as exploited, so confirm the exact impact.","search":"'-0296':18A,21A '-2018':17A,20A '1000v':209C '2100':246C '3000':202C '4100':251C '5500':213C,219C '6500':232C '7600':237C '9300':256C 'adapt':2A,7A,71C,215C,240C 'adaptive':23A 'affect':84C,154C,183C 'allow':76C,159C 'also':99C 'appli':174C 'applianc':4A,9A,73C,206C,217C,243C,249C,254C 'appliance':25A 'asa':5A,10A,26A,27B,36B,74C,107C,185C,208C,212C,218C,226C,257C 'asav':244C 'attack':53B,80C,113C,141C,161C 'authent':120C 'bug':264C 'catalyst':231C 'caus':82C,163C 'certain':102C 'cisco':1A,6A,22A,28B,35B,70C,184C,188C,200C,230C,236C,263C 'cloud':210C 'condit':96C,166C 'could':75C,114C,142C,158C 'craft':47B,149C 'crash':55B 'cscvi16029':266C 'cve':16A,19A 'defens':191C 'denial':12A,92C 'denial-of-servic':11A 'devic':57B,85C,155C 'directori':123C 'disclosur':169C 'dos':95C,165C 'due':129C 'exploit':29B,143C,157C 'firepow':189C,245C,250C,255C 'firewal':30B,37B,211C,225C 'flaw':42B 'follow':199C 'ftd':192C,260C 'ftdv':262C 'generat':224C 'handl':46B 'host':34B 'http':48B,138C,150C,179C 'id':265C 'industri':204C 'inform':61B,118C,171C 'infrastructur':31B 'input':40B,134C 'interfac':67C 'ipv4':176C 'ipv6':178C 'isa':207C 'lack':131C 'modul':228C,259C 'next':223C 'next-gener':222C 'possibl':100C 'product':201C 'proper':133C 'read':59B 'releas':104C 'reload':87C,110C 'remot':52B,79C 'request':151C 'result':89C 'router':239C 'run':196C 'secur':3A,8A,72C,205C,216C,241C,248C,253C,258C 'security':24A 'self':33B 'self-host':32B 'send':147C 'sensit':116C 'seri':203C,214C,221C,233C,238C,247C,252C 'servic':14A,94C,227C 'softwar':103C,186C,193C 'switch':234C 'system':117C 'techniqu':125C 'threat':190C 'traffic':180C 'travers':124C 'unauthent':51B,78C,168C 'unexpect':88C 'url':49B,139C 'use':122C 'valid':41B,135C 'view':115C 'virtual':242C,261C 'vulner':15A,63C,127C,145C,173C,182C 'web':66C 'without':119C 'x':220C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2018-06-07T12:29:00+00:00","kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2018-0296","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-0296","severity":null,"published_at":"2021-11-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:53+00:00","fetched_at":"2026-10-25T16:39:49+00:00","note":null},{"source":"epss","external_id":"CVE-2018-0296","url":"https://api.first.org/data/v1/epss?cve=CVE-2018-0296","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2018-0296","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-0296","severity":null,"published_at":"2018-06-07T12:29:00+00:00","modified_at":"2026-08-11T19:37:30+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}