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.
problem types: CWE-755 Improper Handling of Exceptional Conditions
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 19.3R3-S2, status: unaffected, version: unspecified, versionType: custom
status: affected, version: 19.3R3-S2
status: affected, version: 19.4R3-S3
lessThan: 20.1*, status: unaffected, version: 20.1R1, versionType: custom
changes: [at: 20.2R3-S2, status: unaffected], lessThan: 20.2R2-S3, status: unaffected, version: 20.2, versionType: custom
changes: [at: 20.3R3, status: unaffected], lessThan: 20.3R2, status: unaffected, version: 20.3, versionType: custom
changes: [at: 20.4R3, status: unaffected], lessThan: 20.4R2, status: unaffected, version: 20.4, versionType: custom
lessThan: 21.1R2, status: affected, version: 21.1, versionType: custom
}
{
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 20.4R2-S3-EVO, 20.4R3-EVO, status: affected, version: unspecified, versionType: custom
lessThan: 21.1R2-EVO, status: affected, version: 21.1-EVO, versionType: custom
lessThan: 21.2R2-EVO, status: affected, version: 21.2-EVO, versionType: custom
}
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
]
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue:
Junos 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.
Junos OS Evolved 20.4R2-S3-EVO, 20.4R3-EVO, 21.1R2-EVO, 21.2R2-EVO, 21.3R1-EVO, and all subsequent releases.
Note: 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.
workarounds: This issue can be mitigated in two ways:
1) ensure that TTL propagation is either enabled or disabled in both places below:
protocols mpls no-propagate-ttl
routing-instance <vrf> no-vrf-propagate-ttl
2) Disable multipath:
routing-instance <vrf> routing-options multipath