{"api_version":"1","generated_at":"2026-07-23T11:24:54+00:00","cve":"CVE-2021-31353","urls":{"html":"https://cve.report/CVE-2021-31353","api":"https://cve.report/api/cve/CVE-2021-31353.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2021-31353","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-31353"},"summary":{"title":"CVE-2021-31353","description":"An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon (RPD) to crash and restart, leading to a Denial of Service (DoS). Continued receipt and processing of the BGP update will create a sustained Denial of Service (DoS) condition. This issue affects very specific versions of Juniper Networks Junos OS: 19.3R3-S2; 19.4R3-S3; 20.2 versions 20.2R2-S3 and later, prior to 20.2R3-S2; 20.3 versions 20.3R2 and later, prior to 20.3R3; 20.4 versions 20.4R2 and later, prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS 20.1 is not affected by this issue. This issue also affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO, 20.4R3-EVO; 21.1-EVO versions prior to 21.1R2-EVO; 21.2-EVO versions prior to 21.2R2-EVO.","state":"PUBLIC","assigner":"sirt@juniper.net","published_at":"2021-10-19 19:15:00","updated_at":"2021-10-25 21:41:00"},"problem_types":["CWE-755"],"metrics":[],"references":[{"url":"https://kb.juniper.net/JSA11218","name":"https://kb.juniper.net/JSA11218","refsource":"CONFIRM","tags":[],"title":"2021-10 Security Bulletin: Junos OS and Junos OS Evolved: RPD core upon receipt of specific BGP update (CVE-2021-31353) - Juniper Networks","mime":"text/html","httpstatus":"200","archivestatus":"404"},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-31353","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-31353","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"19.3","cpe7":"r3-s2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"19.4","cpe7":"r3-s3","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.2","cpe7":"r2-s3","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.2","cpe7":"r3","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.2","cpe7":"r3-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.3","cpe7":"r2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.3","cpe7":"r2-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.4","cpe7":"r2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"20.4","cpe7":"r2-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"21.1","cpe7":"r1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos","cpe6":"21.1","cpe7":"r1-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"20.4","cpe7":"r1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"20.4","cpe7":"r1-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"20.4","cpe7":"r1-s2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"20.4","cpe7":"r2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"20.4","cpe7":"r2-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"20.4","cpe7":"r2-s2","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"21.1","cpe7":"r1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cpe1":"cpe","cpe2":"2.3","cpe3":"o","cpe4":"juniper","cpe5":"junos_os_evolved","cpe6":"21.1","cpe7":"r1-s1","cpe8":"*","cpe9":"*","cpe10":"*","cpe11":"*","cpe12":"*","cpe13":"*"},{"cve_year":"2021","cve_id":"31353","vulnerable":"1","versionEndIncluding":"","cp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OS and Junos OS Evolved: RPD core upon receipt of specific BGP update"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"Junos OS","version":{"version_data":[{"version_affected":"!<","version_value":"19.3R3-S2"},{"version_affected":"=","version_value":"19.3R3-S2"},{"version_affected":"=","version_value":"19.4R3-S3"},{"version_affected":"!>=","version_name":"20.1","version_value":"20.1R1"},{"version_affected":"!<","version_name":"20.2","version_value":"20.2R2-S3"},{"version_affected":"<","version_name":"20.2","version_value":"20.2R3-S2"},{"version_affected":"!<","version_name":"20.3","version_value":"20.3R2"},{"version_affected":"<","version_name":"20.3","version_value":"20.3R3"},{"version_affected":"!<","version_name":"20.4","version_value":"20.4R2"},{"version_affected":"<","version_name":"20.4","version_value":"20.4R3"},{"version_affected":"<","version_name":"21.1","version_value":"21.1R2"}]}},{"product_name":"Junos OS Evolved","version":{"version_data":[{"version_affected":"<","version_value":"20.4R2-S3-EVO, 20.4R3-EVO"},{"version_affected":"<","version_name":"21.1-EVO","version_value":"21.1R2-EVO"},{"version_affected":"<","version_name":"21.2-EVO","version_value":"21.2R2-EVO"}]}}]},"vendor_name":"Juniper Networks"}]}},"configuration":[{"lang":"eng","value":"This issue can occur when multipath is enabled:\n\n  routing-instance <vrf> routing-options multipath\n\nand one of the following two TTL propagation options (but not both) are enabled:\n\n  protocols mpls no-propagate-ttl\n  routing-instance <vrf> no-vrf-propagate-ttl\n"}],"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon (RPD) to crash and restart, leading to a Denial of Service (DoS). Continued receipt and processing of the BGP update will create a sustained Denial of Service (DoS) condition. This issue affects very specific versions of Juniper Networks Junos OS: 19.3R3-S2; 19.4R3-S3; 20.2 versions 20.2R2-S3 and later, prior to 20.2R3-S2; 20.3 versions 20.3R2 and later, prior to 20.3R3; 20.4 versions 20.4R2 and later, prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS 20.1 is not affected by this issue. This issue also affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO, 20.4R3-EVO; 21.1-EVO versions prior to 21.1R2-EVO; 21.2-EVO versions prior to 21.2R2-EVO."}]},"exploit":[{"lang":"eng","value":"Juniper SIRT is not aware of any malicious exploitation of this vulnerability."}],"generator":{"engine":"Vulnogram 0.0.9"},"impact":{"cvss":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"CWE-755 Improper Handling of Exceptional Conditions"}]}]},"references":{"reference_data":[{"name":"https://kb.juniper.net/JSA11218","refsource":"CONFIRM","url":"https://kb.juniper.net/JSA11218"}]},"solution":[{"lang":"eng","value":"The following software releases have been updated to resolve this specific issue: \n\nJunos OS 18.4R2-S9, 19.1R3-S7, 19.3R3-S3, 19.4R1-S4, 19.4R3-S4, 20.1R3, 20.2R3-S2, 20.3R3, 20.4R3, 21.1R2, 21.2R1, 21.2R2, 21.3R1, and all subsequent releases.\n\nJunos OS Evolved 20.4R2-S3-EVO, 20.4R3-EVO, 21.1R2-EVO, 21.2R2-EVO, 21.3R1-EVO, and all subsequent releases.\n\nNote: Only those releases listed in the PROBLEM section above are affected.  This fix has also been proactively committed into other releases that are not vulnerable to this issue."}],"source":{"advisory":"JSA11218","defect":["1595165"],"discovery":"USER"},"work_around":[{"lang":"eng","value":"This issue can be mitigated in two ways:\n\n1) ensure that TTL propagation is either enabled or disabled in both places below:\n  protocols mpls no-propagate-ttl\n  routing-instance <vrf> no-vrf-propagate-ttl\n\n2) Disable multipath:\n  routing-instance <vrf> routing-options multipath \n"}]},"nvd":{"publishedDate":"2021-10-19 19:15:00","lastModifiedDate":"2021-10-25 21:41:00","problem_types":["CWE-755"],"metrics":{"baseMetricV3":{"cvssV3":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6},"baseMetricV2":{"cvssV2":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:N/I:N/A:P","accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"PARTIAL","baseScore":5},"severity":"MEDIUM","exploitabilityScore":10,"impactScore":2.9,"acInsufInfo":false,"obtainAllPrivilege":false,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}},"configurations":{"CVE_data_version":"4.0","nodes":[{"operator":"OR","children":[],"cpe_match":[{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:20.4:r1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.2:r2-s3:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.3:r2:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:21.1:r1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.4:r2:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.3:r2-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.2:r3:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.2:r3-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:19.4:r3-s3:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:19.3:r3-s2:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:20.4:r2-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos:21.1:r1-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:21.1:r1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:21.1:r1-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:21.2:r1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:21.2:r1-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:20.4:r1-s2:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:20.4:r2:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s1:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:20.4:r2-s2:*:*:*:*:*:*","cpe_name":[]},{"vulnerable":true,"cpe23Uri":"cpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*","versionEndIncluding":"20.3","cpe_name":[]}]}]}},"legacy_mitre":{"record":{"CveYear":"2021","CveId":"31353","Ordinal":"206638","Title":"CVE-2021-31353","CVE":"CVE-2021-31353","Year":"2021"},"notes":[{"CveYear":"2021","CveId":"31353","Ordinal":"1","NoteData":"An Improper Handling of Exceptional Conditions vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an attacker to inject a specific BGP update, causing the routing protocol daemon (RPD) to crash and restart, leading to a Denial of Service (DoS). Continued receipt and processing of the BGP update will create a sustained Denial of Service (DoS) condition. This issue affects very specific versions of Juniper Networks Junos OS: 19.3R3-S2; 19.4R3-S3; 20.2 versions 20.2R2-S3 and later, prior to 20.2R3-S2; 20.3 versions 20.3R2 and later, prior to 20.3R3; 20.4 versions 20.4R2 and later, prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS 20.1 is not affected by this issue. This issue also affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-S3-EVO, 20.4R3-EVO; 21.1-EVO versions prior to 21.1R2-EVO; 21.2-EVO versions prior to 21.2R2-EVO.","Type":"Description","Title":null},{"CveYear":"2021","CveId":"31353","Ordinal":"2","NoteData":"2021-10-19","Type":"Other","Title":"Published"},{"CveYear":"2021","CveId":"31353","Ordinal":"3","NoteData":"2021-10-19","Type":"Other","Title":"Modified"}]}}}