title: Junos OS and Junos OS Evolved: Due to a race condition the rpd process can crash upon receipt of a BGP update message containing flow spec route
description: A Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in Routing Protocol Daemon (rpd) of Juniper Networks Junos OS, Junos OS Evolved allows a network-based unauthenticated attacker to cause a Denial of Service (DoS). When a BGP flow route with redirect IP extended community is received, and the reachability to the next-hop of the corresponding redirect IP is flapping, the rpd process might crash. Whether the crash occurs depends on the timing of the internally processing of these two events and is outside the attackers control. Please note that this issue also affects Route-Reflectors unless 'routing-options flow firewall-install-disable' is configured. This issue affects: Juniper Networks Junos OS: 18.4 versions prior to 18.4R2-S10, 18.4R3-S10; 19.1 versions prior to 19.1R3-S7; 19.2 versions prior to 19.2R1-S8, 19.2R3-S4; 19.4 versions prior to 19.4R3-S8; 20.2 versions prior to 20.2R3-S3; 20.3 versions prior to 20.3R3-S2; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R2. Juniper Networks Junos OS Evolved: All versions prior to 20.4R2-EVO; 21.1-EVO versions prior to 21.1R2-EVO. This issue does not affect Juniper Networks Junos OS versions prior to 18.4R1.
problem types: CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
affected:
{
vendor: Juniper Networks
product: Junos OS
versions:
version: unspecified, lessThan: 18.4R1, status: unaffected, versionType: custom
version: 18.4, status: affected, lessThan: 18.4R2-S10, 18.4R3-S10, versionType: custom
version: 19.1, status: affected, lessThan: 19.1R3-S7, versionType: custom
version: 19.2, status: affected, lessThan: 19.2R1-S8, 19.2R3-S4, versionType: custom
version: 19.4, status: affected, lessThan: 19.4R3-S8, versionType: custom
version: 20.2, status: affected, lessThan: 20.2R3-S3, versionType: custom
version: 20.3, status: affected, lessThan: 20.3R3-S2, versionType: custom
version: 20.4, status: affected, lessThan: 20.4R3, versionType: custom
version: 21.1, status: affected, lessThan: 21.1R2, versionType: custom
}
{
vendor: Juniper Networks
product: Junos OS Evolved
versions:
version: unspecified, lessThan: 20.4R2-EVO, status: affected, versionType: custom
version: 21.1-EVO, status: affected, lessThan: 21.1R2-EVO, versionType: custom
}
metrics:
cvssV3_1: [
version: 3.1
vectorString: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
attackVector: NETWORK
attackComplexity: HIGH
privilegesRequired: NONE
userInteraction: NONE
scope: UNCHANGED
confidentialityImpact: NONE
integrityImpact: NONE
availabilityImpact: HIGH
baseScore: 5.9
baseSeverity: MEDIUM
]
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-S10, 18.4R3-S10, 19.1R3-S7, 19.2R1-S8, 19.2R3-S4, 19.4R3-S8, 20.2R3-S3, 20.3R3-S2, 20.4R3, 21.1R2, 21.2R1, and all subsequent releases.
Junos OS Evolved: 20.4R2-EVO, 21.1R2-EVO, 21.2R1-EVO, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.