{"id":"CVE-2021-31353","state":"PUBLISHED","title":"Junos OS and Junos OS Evolved: RPD core upon receipt of specific BGP update","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.","publishedAt":"2021-10-19T18:16:34.884Z","updatedAt":"2024-09-16T17:37:46.150Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"juniper"},"assigner":"juniper","products":["Juniper Networks Junos OS","Juniper Networks Junos OS Evolved"],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","versions":[{"version":"unspecified","status":"unaffected","lessThan":"19.3R3-S2","versionType":"custom"},{"version":"19.3R3-S2","status":"affected"},{"version":"19.4R3-S3","status":"affected"},{"version":"20.1R1","status":"unaffected","lessThan":"20.1*","versionType":"custom"},{"version":"20.2","status":"unaffected","lessThan":"20.2R2-S3","changes":[{"at":"20.2R3-S2","status":"unaffected"}],"versionType":"custom"},{"version":"20.3","status":"unaffected","lessThan":"20.3R2","changes":[{"at":"20.3R3","status":"unaffected"}],"versionType":"custom"},{"version":"20.4","status":"unaffected","lessThan":"20.4R2","changes":[{"at":"20.4R3","status":"unaffected"}],"versionType":"custom"},{"version":"21.1","status":"affected","lessThan":"21.1R2","versionType":"custom"}]},{"vendor":"Juniper Networks","product":"Junos OS Evolved","versions":[{"version":"unspecified","status":"affected","lessThan":"20.4R2-S3-EVO, 20.4R3-EVO","versionType":"custom"},{"version":"21.1-EVO","status":"affected","lessThan":"21.1R2-EVO","versionType":"custom"},{"version":"21.2-EVO","status":"affected","lessThan":"21.2R2-EVO","versionType":"custom"}]}],"references":["https://kb.juniper.net/JSA11218"],"weaknesses":["CWE-755"],"ingestedAt":"2026-10-29T19:48:30.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/31xxx/CVE-2021-31353.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-31353","state":"PUBLISHED","datePublished":"2021-10-19T18:16:34.884Z","dateUpdated":"2024-09-16T17:37:46.150Z","assignerShortName":"juniper","assignerOrgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateReserved":"2021-04-15T00:00:00.000Z"},"containers":{"cna":{"title":"Junos OS and Junos OS Evolved: RPD core upon receipt of specific BGP update","descriptions":[{"lang":"en","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."}],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","versions":[{"version":"unspecified","status":"unaffected","lessThan":"19.3R3-S2","versionType":"custom"},{"version":"19.3R3-S2","status":"affected"},{"version":"19.4R3-S3","status":"affected"},{"version":"20.1R1","status":"unaffected","lessThan":"20.1*","versionType":"custom"},{"version":"20.2","status":"unaffected","lessThan":"20.2R2-S3","changes":[{"at":"20.2R3-S2","status":"unaffected"}],"versionType":"custom"},{"version":"20.3","status":"unaffected","lessThan":"20.3R2","changes":[{"at":"20.3R3","status":"unaffected"}],"versionType":"custom"},{"version":"20.4","status":"unaffected","lessThan":"20.4R2","changes":[{"at":"20.4R3","status":"unaffected"}],"versionType":"custom"},{"version":"21.1","status":"affected","lessThan":"21.1R2","versionType":"custom"}]},{"vendor":"Juniper Networks","product":"Junos OS Evolved","versions":[{"version":"unspecified","status":"affected","lessThan":"20.4R2-S3-EVO, 20.4R3-EVO","versionType":"custom"},{"version":"21.1-EVO","status":"affected","lessThan":"21.1R2-EVO","versionType":"custom"},{"version":"21.2-EVO","status":"affected","lessThan":"21.2R2-EVO","versionType":"custom"}]}],"references":[{"url":"https://kb.juniper.net/JSA11218","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-755","description":"CWE-755 Improper Handling of Exceptional Conditions","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"juniper","dateUpdated":"2021-10-19T18:16:34.000Z","orgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968"},"configurations":[{"lang":"en","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"}],"datePublic":"2021-10-13T00:00:00.000Z","exploits":[{"lang":"en","value":"Juniper SIRT is not aware of any malicious exploitation of this vulnerability."}],"solutions":[{"lang":"en","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"},"workarounds":[{"lang":"en","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"}],"x_generator":{"engine":"Vulnogram 0.0.9"},"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"sirt@juniper.net","DATE_PUBLIC":"2021-10-13T16:00:00.000Z","ID":"CVE-2021-31353","STATE":"PUBLIC","TITLE":"Junos 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":"en","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"}],"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":"en","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":"en","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":"en","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"}]}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://kb.juniper.net/JSA11218","tags":["x_refsource_CONFIRM","x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-03T22:55:53.456Z"}}]}}}