{"id":"CVE-2023-36851","kind":"vulnerability","aliases":["CVE-2023-36851"],"related":[],"title":"juniper junos: A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an…","description":"A Missing Authentication for Critical Function vulnerability in Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause limited impact to the file system integrity.\n\n\n\nWith a specific request to \n\nwebauth_operation.php\n\nthat doesn't require authentication, an attacker is able to upload and download arbitrary files via J-Web, leading to a loss of \n\nintegrity or confidentiality, which may allow chaining to other vulnerabilities.\n\n\nThis issue affects Juniper Networks Junos OS on SRX Series:\n\n\n\n  *  \n\n21.2 versions prior to 21.2R3-S8;\n  *  21.4 \n\nversions prior to \n\n21.4R3-S6;\n  *  22.1 \n\nversions prior to \n\n22.1R3-S5;\n  *  22.2 \n\nversions prior to \n\n22.2R3-S3;\n  *  22.3 \n\nversions prior to \n\n22.3R3-S2;\n  *  22.4 versions prior to 22,4R2-S2, 22.4R3;\n  *  23.2 versions prior to \n\n23.2R1-S2, 23.2R2.","summary":"Juniper Junos OS on SRX firewalls has a J-Web endpoint (webauth_operation.php) that accepts requests without authentication. An unauthenticated network attacker can upload arbitrary files to the device, which compromises file system integrity and may be chained into further attacks.","severity":"high","cvss":5.3,"epss":null,"exploited":true,"exploited_at":"2023-11-13T00:00:00+00:00","products":[{"name":"Juniper Junos OS","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 21.2","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 21.4","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 22.1","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 22.2","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 22.3","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 22.4","ecosystem":"vendor"},{"name":"juniper junos","fixed":[],"affected":"= 23.2","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","j-web","juniper","junos-os","srx-series"],"not_affected_if":["j-web-disabled","non-srx-platform"],"how_to_check":null,"fix":"Apply the mitigation or fixed Junos OS release per Juniper's vendor advisory (CISA requires mitigations or discontinuing use if none exist). Version details: unknown.","status":"open","published_at":"2023-09-27T15:18:54+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T21:02:53+00:00","updated_at":"2026-10-23T22:29:04+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:02:53Z","model":"claude-haiku-5-5","output":{"fix":"Apply the mitigation or fixed Junos OS release per Juniper's vendor advisory (CISA requires mitigations or discontinuing use if none exist). Version details: unknown.","reach":"network","impact":"high","summary":"Juniper Junos OS on SRX firewalls has a J-Web endpoint (webauth_operation.php) that accepts requests without authentication. An unauthenticated network attacker can upload arbitrary files to the device, which compromises file system integrity and may be chained into further attacks.","category":"infrastructure","who_cares":["juniper","junos-os","srx-series","j-web"],"confidence":0.6,"needs_auth":"no","worst_case":"Unauthenticated attacker uploads arbitrary files to the firewall, enabling chained compromise","analyst_note":"Find the Juniper advisory for CVE-2023-36851 to confirm affected and fixed Junos versions, the J-Web mitigation, and whether J-Web disabled removes exposure.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["j-web-disabled","non-srx-platform"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"high"},"cost_usd":0.000503,"input_tokens":2918,"output_tokens":423,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2023':20A,23A '-36851':21A,24A '21.2':176C,180C '21.4':184C,188C '22':220C '22.1':192C,196C '22.2':200C,204C '22.3':208C,212C '22.4':216C,224C '23.2':226C,230C,234C '4r2':222C '4r2-s2':221C 'abl':140C 'accept':68B 'affect':168C 'allow':18A,110C,161C 'arbitrari':78B,145C 'attack':75B,94B,116C,138C 'authent':5A,71B,97C,136C 'base':115C 'caus':118C 'chain':91B,162C 'compromis':84B 'confidenti':158C 'critic':7A,99C 'cve':19A,22A 'devic':82B 'doesn':133C 'download':144C 'endpoint':65B 'exploit':42B 'file':79B,85B,123C,146C 'firewal':59B 'function':8A,100C 'impact':120C 'infrastructur':43B 'integr':87B,125C,156C 'issu':167C 'j':45B,63B,149C 'j-web':44B,62B,148C 'junip':1A,11A,47B,54B,103C,169C 'juniper':25A,28A,30A,32A,34A,36A,38A,40A 'juno':2A,13A,49B,55B,105C,171C 'junos':26A,29A,31A,33A,35A,37A,39A,41A 'junos-o':48B 'lead':151C 'limit':119C 'loss':154C 'may':89B,160C 'miss':4A,96C 'network':12A,74B,104C,114C,170C 'network-bas':113C 'os':14A,27A,50B,56B,106C,172C 'prior':178C,186C,194C,202C,210C,218C,228C 'r1':232C 'r1-s2':231C 'r2':235C 'r3':182C,190C,198C,206C,214C,225C 'r3-s2':213C 'r3-s3':205C 'r3-s5':197C 'r3-s6':189C 'r3-s8':181C 'request':69B,129C 'requir':135C 's2':215C,223C,233C 's3':207C 's5':199C 's6':191C 's8':183C 'seri':17A,53B,109C,175C 'specif':128C 'srx':16A,52B,58B,108C,174C 'srx-seri':51B 'system':86B,124C 'unauthent':73B,112C 'upload':77B,142C 'version':177C,185C,193C,201C,209C,217C,227C 'via':147C 'vulner':9A,101C,165C 'web':46B,64B,150C 'webauth_operation.php':66B,131C 'without':70B","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-09-27T15:18:54+00:00","kev":{"dateAdded":"2023-11-13","dueDate":"2023-11-17","requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","cvss_by":"sirt@juniper.net","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2023-36851","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-36851","severity":null,"published_at":"2023-11-13T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T13:39:30+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-36851","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-36851","severity":null,"published_at":"2023-09-27T15:18:54+00:00","modified_at":"2026-06-17T06:07:13+00:00","first_seen_at":"2026-10-23T22:29:04+00:00","fetched_at":"2026-10-23T22:29:04+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"}