An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX7000 Series allows an unauthenticated network-based attacker to cause a partial Denial of Service (DoS).
On receipt of specific IPv6 transit traffic, Junos OS Evolved on ACX7100-48L, ACX7100-32C and ACX7509 sends this traffic to the Routing Engine (RE) instead of forwarding it, leading to increased CPU utilization of the RE and a partial DoS.
This issue only affects systems configured with IPv6.This issue does not affect ACX7024 which is supported from 22.3R1-EVO onwards where the fix has already been incorporated as indicated in the solution section.
This issue affects Juniper Networks Junos OS Evolved on ACX7100-48L, ACX7100-32C, ACX7509:
This issue does not affect Juniper Networks Junos OS Evolved versions prior to 21.1R1-EVO.
To be exposed to this vulnerability a device needs to be configured with a minimal IPv6 configuration like in the following example:
[interfaces <interface> unit <unit number> family inet6]
Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
This issue was seen during production usage.
This issue has been assigned CVE-2022-22227.
The following software releases have been updated to resolve this specific issue: 21.1R3-S2-EVO, 21.2R3-S2-EVO, 21.3R3-EVO, 21.4R1-S1-EVO, 21.4R2-EVO, 22.1R1-EVO, and all subsequent releases.
This issue is being tracked as PR 1641006 which is visible on the Customer Support website.
Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).
Software Releases, patches and updates are available at https://support.juniper.net/support/downloads/.