{"id":"CVE-2023-36851","published":"2023-09-27T15:18:54Z","modified":"2026-06-17T06:07:13Z","title":"Juniper Junos OS SRX Series Missing Authentication for Critical Function Vulnerability","vendor":"Juniper","product":"Junos OS","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"A Missing Authentication for Critical Function flaw in Juniper Networks Junos OS on SRX Series lets a remote attacker reach the J-Web interface through a request to webauth_operation.php that bypasses authentication, enabling upload and download of arbitrary files. The attack needs only network access and no credentials or user interaction, and it primarily affects file system integrity, with possible chaining to other vulnerabilities.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:14:56Z"},"cvss":{"score":5.3,"severity":"MEDIUM","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","provenance":"source","from":"NVD"},"epss":{"score":0.01123,"percentile":0.66166,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2023-11-13","dueDate":"2023-11-17","ransomware":false,"requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","notes":"https://supportportal.juniper.net/s/article/2023-08-Out-of-Cycle-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Multiple-vulnerabilities-in-J-Web-can-be-combined-to-allow-a-preAuth-Remote-Code-Execution?language=en_US ;  https://nvd.nist.gov/vuln/detail/CVE-2023-36851","provenance":"source"},"vulncheckKev":{"dateAdded":"2023-08-29","exploitedFirstSeen":"2023-08-29","ransomware":false,"evidence":[{"url":"https://twitter.com/Shadowserver/status/1696512418036486246","date":"2023-08-29"},{"url":"https://supportportal.juniper.net/s/article/2023-08-Out-of-Cycle-Security-Bulletin-Junos-OS-SRX-Series-and-EX-Series-Multiple-vulnerabilities-in-J-Web-can-be-combined-to-allow-a-preAuth-Remote-Code-Execution","date":"2023-11-08"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2023-11-13"},{"url":"https://www.tenable.com/blog/verizon-2025-dbir-tenable-research-collaboration","date":"2025-04-23"},{"url":"https://www.verizon.com/business/resources/T32e/reports/2025-dbir-data-breach-investigations-report.pdf","date":"2025-04-25"}],"evidenceTotal":5,"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-306","name":"Missing Authentication for Critical Functionality"}],"references":[{"url":"https://supportportal.juniper.net/JSA72300","tags":["Vendor Advisory"]},{"url":"https://supportportal.juniper.net/JSA72300","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-36851","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Missing Authentication","mappingType":"exploitation_technique","evidence":[],"comment":"This vulnerability is exploited through a Missing Authentication for Critical Function weakness in Juniper Networks Junos OS on SRX Series devices. Attackers leverage this vulnerability to impact file system integrity by sending a crafted request to the `webauth_operation.php` endpoint, which does not require authentication. This manipulation allows attackers to cause limited impact to the file system integrity, potentially enabling further exploitation.","confidence":"high"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Missing Authentication","mappingType":"primary_impact","evidence":[],"comment":"This vulnerability is exploited through a Missing Authentication for Critical Function weakness in Juniper Networks Junos OS on SRX Series devices. Attackers leverage this vulnerability to impact file system integrity by sending a crafted request to the `webauth_operation.php` endpoint, which does not require authentication. This manipulation allows attackers to cause limited impact to the file system integrity, potentially enabling further exploitation.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2023-40771","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-40771","exploited":true,"exploitedSince":"2023-11-13","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"source"},{"stage":"primary","techniques":["T1059"],"provenance":"source"}],"timeline":[{"date":"2023-08-29","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://twitter.com/Shadowserver/status/1696512418036486246","provenance":"source"},{"date":"2023-09-27","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-36851","provenance":"source"},{"date":"2023-11-13","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2023-11-13","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-40771","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":47},"priority":{"score":54.9,"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 1157 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":13.23,"detail":"percentile 0.6617"},{"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":3.71,"detail":"base score 5.3"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}