{"id":"CVE-2021-0208","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-0208","generatedAt":"2026-10-28T01:51:50.889Z","title":"An improper input validation vulnerability in the Routing Protocol Daemon (RPD) service of Juniper Networks Junos OS allows an attacker to send a malformed RSVP packet when bidirectional LSPs are in use, which when received by an egress router crashes…","description":"An improper input validation vulnerability in the Routing Protocol Daemon (RPD) service of Juniper Networks Junos OS allows an attacker to send a malformed RSVP packet when bidirectional LSPs are in use, which when received by an egress router crashes the RPD causing a Denial of Service (DoS) condition. Continued receipt of the packet will sustain the Denial of Service. This issue affects: Juniper Networks Junos OS: All versions prior to 17.3R3-S10 except 15.1X49-D240 for SRX series; 17.4 versions prior to 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R2-S7, 18.2R3-S4; 18.3 versions prior to 18.3R3-S2; 18.4 versions prior to 18.4R1-S8, 18.4R2-S6, 18.4R3-S2; 19.1 versions prior to 19.1R1-S5, 19.1R3-S3; 19.2 versions prior to 19.2R3; 19.3 versions prior to 19.3R2-S5, 19.3R3; 19.4 versions prior to 19.4R2-S2, 19.4R3-S1; 20.1 versions prior to 20.1R1-S4, 20.1R2; 15.1X49 versions prior to 15.1X49-D240 on SRX Series. Juniper Networks Junos OS Evolved: 19.3 versions prior to 19.3R2-S5-EVO; 19.4 versions prior to 19.4R2-S2-EVO; 20.1 versions prior to 20.1R1-S4-EVO.","published":"2021-01-15T18:15:15.000Z","lastModified":"2026-06-17T03:29:29.000Z","status":"Modified","sourceIdentifier":"sirt@juniper.net","cvss":{"version":"3.1","score":8.8,"severity":"HIGH","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-20"],"affected":["juniper/junos","juniper/junos os evolved"],"epss":{"score":0.00658,"percentile":0.51186,"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 (0.66%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://kb.juniper.net/JSA11098","tags":["Vendor Advisory"],"source":"sirt@juniper.net"},{"url":"https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/corouted-bidirectional-edit-protocols-mpls.html","tags":["Vendor Advisory"],"source":"sirt@juniper.net"},{"url":"https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/disable-edit-protocols-rsvp.html","tags":["Vendor Advisory"],"source":"sirt@juniper.net"},{"url":"https://kb.juniper.net/JSA11098","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/corouted-bidirectional-edit-protocols-mpls.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.juniper.net/documentation/en_US/junos/topics/reference/configuration-statement/disable-edit-protocols-rsvp.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-0208","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."}