CVE-2021-31382 : Vulnerability Insights and Analysis
Learn about CVE-2021-31382, a vulnerability in Juniper Networks Junos OS impacting PTX1000 and PTX10002-60C Systems. Understand the impact, affected versions, and mitigation steps.
This article provides detailed information about CVE-2021-31382, a vulnerability in Juniper Networks Junos OS affecting PTX1000 and PTX10002-60C Systems.
Understanding CVE-2021-31382
CVE-2021-31382 is a Race Condition vulnerability in Juniper Networks Junos OS that may result in incorrect firewall filters being applied to device interfaces after upgrading to an affected release.
What is CVE-2021-31382?
The vulnerability arises due to a Race Condition between the chassis daemon (chassisd) and firewall process (dfwd), potentially allowing genuine traffic to propagate further, leading to service disruptions and potential exploitation by attackers.
The Impact of CVE-2021-31382
The misassignment of firewall rules can cause disruptions in services by allowing undesired traffic to pass through interfaces, impacting the security and integrity of the system.
Technical Details of CVE-2021-31382
The vulnerability affects Junos OS on PTX1000 System versions 17.2R1 and later, up to version 20.4, and on PTX10002-60C System versions 18.2R1 and later, up to version 21.3. It impacts all filter families and loopback filters.
Vulnerability Description
Interfaces may have incorrect firewall filter assignments after upgrading to certain affected releases, potentially allowing unwanted traffic to pass through.
Affected Systems and Versions
PTX1000 System: Versions 17.2R1 and later up to 20.4. PTX10002-60C System: Versions 18.2R1 and later up to 21.3. Exact version details can be found in the Juniper advisory.
Exploitation Mechanism
Juniper SIRT has not detected any malicious exploitation of this vulnerability at the time of reporting.
Mitigation and Prevention
After upgrading to the recommended software releases, the vulnerability can be mitigated. Restarting the firewall daemon post-reboot is advised as a temporary workaround.
Immediate Steps to Take
Ensure that the Junos OS software on affected systems is updated to the versions specified in the Juniper advisory to prevent exploitation.
Long-Term Security Practices
Regularly update Junos OS on affected systems and follow best practices for network security and monitoring.
Patching and Updates
Refer to the Juniper advisory for a list of software releases that address and resolve the CVE-2021-31382 vulnerability.