CVE-2021-31382

/// Technical description

On PTX1000 System, PTX10002-60C System, after upgrading to an affected release, a Race Condition vulnerability between the chassis daemon (chassisd) and firewall process (dfwd) of Juniper Networks Junos OS, may update the device's interfaces with incorrect firewall filters. This issue only occurs when upgrading the device to an affected version of Junos OS. Interfaces intended to have protections may have no protections assigned to them. Interfaces with one type of protection pattern may have alternate protections assigned to them. Interfaces intended to have no protections may have protections assigned to them. These firewall rule misassignments may allow genuine traffic intended to be stopped at the interface to propagate further, potentially causing disruptions in services by propagating unwanted traffic. An attacker may be able to take advantage of these misassignments. This issue affects Juniper Networks Junos OS on PTX1000 System: 17.2 versions 17.2R1 and later versions prior to

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References