{ "CVE_data_meta": { "ASSIGNER": "sirt@juniper.net", "DATE_PUBLIC": "2020-10-14T16:00:00.000Z", "ID": "CVE-2020-1662", "STATE": "PUBLIC", "TITLE": "Junos OS and Junos OS Evolved: RPD crash due to BGP session flapping." }, "affects": { "vendor": { "vendor_data": [ { "product": { "product_data": [ { "product_name": "Junos OS", "version": { "version_data": [ { "version_affected": "=", "version_name": "17.2", "version_value": "17.2R3-S3" }, { "version_affected": ">=", "version_name": "17.3", "version_value": "17.3R3-S3" }, { "version_affected": "<", "version_name": "17.3", "version_value": "17.3R3-S8" }, { "version_affected": ">=", "version_name": "17.4", "version_value": "17.4R2-S4, 17.4R3" }, { "version_affected": "<", "version_name": "17.4", "version_value": "17.4R2-S10, 17.4R3-S2" }, { "version_affected": ">=", "version_name": "18.1", "version_value": "18.1R3-S6" }, { "version_affected": "<", "version_name": "18.1", "version_value": "18.1R3-S10" }, { "version_affected": ">=", "version_name": "18.2", "version_value": "18.2R3" }, { "version_affected": "<", "version_name": "18.2", "version_value": "18.2R3-S4" }, { "version_affected": ">=", "version_name": "18.2X75", "version_value": "18.2X75-D50, 18.2X75-D60" }, { "version_affected": "<", "version_name": "18.2X75", "version_value": "18.2X75-D53, 18.2X75-D65" }, { "version_affected": ">=", "version_name": "18.3", "version_value": "18.3R2" }, { "version_affected": "<", "version_name": "18.3", "version_value": "18.3R2-S4, 18.3R3-S2" }, { "version_affected": ">=", "version_name": "18.4", "version_value": "18.4R2" }, { "version_affected": "<", "version_name": "18.4", "version_value": "18.4R2-S5, 18.4R3-S2" }, { "version_affected": ">=", "version_name": "19.1", "version_value": "19.1R1" }, { "version_affected": "<", "version_name": "19.1", "version_value": "19.1R2-S2, 19.1R3-S1" }, { "version_affected": ">=", "version_name": "19.2", "version_value": "19.2R1" }, { "version_affected": "<", "version_name": "19.2", "version_value": "19.2R1-S5, 19.2R2" }, { "version_affected": "<", "version_name": "19.3", "version_value": "19.3R2-S3, 19.3R3" }, { "version_affected": "<", "version_name": "19.4", "version_value": "19.4R1-S3, 19.4R2" }, { "version_affected": "<", "version_name": "20.1", "version_value": "20.1R1-S2, 20.1R2" }, { "version_affected": "!<", "version_value": "17.2R3-S3" } ] } }, { "product_name": "Junos OS Evolved", "version": { "version_data": [ { "version_affected": "=", "version_name": "19.4-EVO", "version_value": "19.4-EVO" }, { "version_affected": "<", "version_name": "20.1-EVO", "version_value": "20.1R2-EVO" } ] } } ] }, "vendor_name": "Juniper Networks" } ] } }, "configuration": [ { "lang": "eng", "value": "The example of the configuration stanza affected by this issue is as follows:\n [protocols bgp damping]\n\nused in combination with accepted-prefix-limit configuration:\n [protocols bgp ... accepted-prefix-limit]\n" } ], "data_format": "MITRE", "data_type": "CVE", "data_version": "4.0", "description": { "description_data": [ { "lang": "eng", "value": "On Juniper Networks Junos OS and Junos OS Evolved devices, BGP session flapping can lead to a routing process daemon (RPD) crash and restart, limiting the attack surface to configured BGP peers. This issue only affects devices with BGP damping in combination with accepted-prefix-limit configuration. When the issue occurs the following messages will appear in the /var/log/messages: rpd[6046]: %DAEMON-4-BGP_PREFIX_THRESH_EXCEEDED: XXXX (External AS x): Configured maximum accepted prefix-limit threshold(1800) exceeded for inet6-unicast nlri: 1984 (instance master) rpd[6046]: %DAEMON-3-BGP_CEASE_PREFIX_LIMIT_EXCEEDED: 2001:x:x:x::2 (External AS x): Shutting down peer due to exceeding configured maximum accepted prefix-limit(2000) for inet6-unicast nlri: 2001 (instance master) rpd[6046]: %DAEMON-4: bgp_rt_maxprefixes_check_common:9284: NOTIFICATION sent to 2001:x:x:x::2 (External AS x): code 6 (Cease) subcode 1 (Maximum Number of Prefixes Reached) AFI: 2 SAFI: 1 prefix limit 2000 kernel: %KERN-5: mastership_relinquish_on_process_exit: RPD crashed on master RE. Sending SIGUSR2 to chassisd (5612:chassisd) to trigger RE switchover This issue affects: Juniper Networks Junos OS: 17.2R3-S3; 17.3 version 17.3R3-S3 and later versions, prior to 17.3R3-S8; 17.4 version 17.4R2-S4, 17.4R3 and later versions, prior to 17.4R2-S10, 17.4R3-S2; 18.1 version 18.1R3-S6 and later versions, prior to 18.1R3-S10; 18.2 version 18.2R3 and later versions, prior to 18.2R3-S4; 18.2X75 version 18.2X75-D50, 18.2X75-D60 and later versions, prior to 18.2X75-D53, 18.2X75-D65; 18.3 version 18.3R2 and later versions, prior to 18.3R2-S4, 18.3R3-S2; 18.4 version 18.4R2 and later versions, prior to 18.4R2-S5, 18.4R3-S2; 19.1 version 19.1R1 and later versions, prior to 19.1R2-S2, 19.1R3-S1; 19.2 version 19.2R1 and later versions, prior to 19.2R1-S5, 19.2R2; 19.3 versions prior to 19.3R2-S3, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2; 20.1 versions prior to 20.1R1-S2, 20.1R2. Juniper Networks Junos OS Evolved prior to 20.1R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 17.2R3-S3." } ] }, "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-20 Improper Input Validation" } ] } ] }, "references": { "reference_data": [ { "name": "https://kb.juniper.net/JSA11059", "refsource": "CONFIRM", "url": "https://kb.juniper.net/JSA11059" } ] }, "solution": [ { "lang": "eng", "value": "The following software releases have been updated to resolve this specific issue:\n\nJunos OS: 17.2R3-S4, 17.3R3-S8, 17.3R3-S9, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R3-S4, 18.2X75-D53, 18.2X75-D65, 18.3R2-S4, 18.3R3-S2, 18.4R2-S5, 18.4R3-S2, 19.1R2-S2, 19.1R3-S1, 19.2R1-S5, 19.2R2, 19.3R2-S3, 19.3R3, 19.4R1-S3, 19.4R2, 20.1R1-S2, 20.1R2, 20.2R1, and all subsequent releases.\n\n\nJunos OS Evolved: 20.1R2-EVO, and all subsequent releases." } ], "source": { "advisory": "JSA11059", "defect": [ "1490079" ], "discovery": "USER" }, "work_around": [ { "lang": "eng", "value": "There are multiple workarounds that can be applied to prevent this issue:\n\n1. Disable BGP router flap damping.\n\n2. Replace \"accepted-prefix-limit\" with \"prefix-limit\" in the BGP configuration, for example: \n [edit protocols bgp group ${GRP} neighbor ${NEI} family ${AFI} unicast] \n + prefix-limit {\n - accepted-prefix-limit {\n\n 3. Make sure that the BGP session idle-timeout is longer than damping max-suppress time. \nIn other words, by the time a peer is eligible to establish BGP session again, no previously advertised prefixes remain suppressed.\nThe BGP session idle time out is configured under:\n [protocols bgp damping ... teardown idle-timeout ]\nThe BGP damping max-suppress time configured under:\n [protocol bgp damping... max-suppress ]\nThe needs to be higher than \n" } ] }