{"id":"CVE-2025-21599","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-21599","generatedAt":"2026-10-28T00:20:50.370Z","title":"A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service.","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the Juniper Tunnel Driver (jtd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause Denial of Service. \n\nReceipt of specifically malformed IPv6 packets, destined to the device, causes kernel memory to not be freed, resulting in memory exhaustion leading to a system crash and Denial of Service (DoS). Continuous receipt and processing of these packets will continue to exhaust kernel memory, creating a sustained Denial of Service (DoS) condition.\nThis issue only affects systems configured with IPv6.\n\nThis issue affects Junos OS Evolved: \n\n\n\n  *  from 22.4-EVO before 22.4R3-S5-EVO, \n  *  from 23.2-EVO before 23.2R2-S2-EVO, \n  *  from 23.4-EVO before 23.4R2-S2-EVO, \n  *  from 24.2-EVO before 24.2R1-S2-EVO, 24.2R2-EVO.\n\n\n\n\nThis issue does not affect Juniper Networks Junos OS Evolved versions prior to 22.4R1-EVO.","published":"2025-01-09T17:15:19.000Z","lastModified":"2026-06-17T08:43:49.000Z","status":"Analyzed","sourceIdentifier":"sirt@juniper.net","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-401"],"affected":["juniper/junos os evolved"],"epss":{"score":0.00605,"percentile":0.4865,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://supportportal.juniper.net/JSA92869","tags":["Vendor Advisory"],"source":"sirt@juniper.net"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-21599","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}