title: Junos OS Evolved: Specific packets reaching the RE lead to a counter overflow and eventually a crash
description: An Improper Update of Reference Count vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to trigger a counter overflow, eventually causing a Denial of Service (DoS). This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S1-EVO; 21.1 versions prior to 21.1R3-EVO; 21.2 versions prior to 21.2R3-EVO; 21.3 versions prior to 21.3R2-EVO. This issue does not affect Juniper Networks Junos OS.
problem types: CWE-911 Improper Update of Reference Count
affected:
{
product: Junos OS Evolved
vendor: Juniper Networks
versions:
lessThan: 20.4R3-S1-EVO, status: affected, version: unspecified, versionType: custom
lessThan: 21.1R3-EVO, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R3-EVO, status: affected, version: 21.2, versionType: custom
lessThan: 21.3R2-EVO, status: affected, version: 21.3, versionType: custom
}
{
product: Junos OS
vendor: Juniper Networks
versions:
status: unaffected, version: any
}
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: 20.4R3-S1-EVO, 21.1R3-EVO, 21.2R3-EVO, 21.3R2-EVO, 21.4R1-EVO, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.
To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted networks, hosts and users.