Junos OS: PTX1000 System, PTX10002-60C System: After upgrading, configured firewall filters may be applied on incorrect interfaces

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 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R1-S8, 18.4R2-S8, 18.4R3-S8; 19.1 versions prior to 19.1R3-S5; 19.2 versions prior to 19.2R3-S2; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R2-S4, 19.4R3-S3; 20.1 versions prior to 20.1R3; 20.2 versions prior to 20.2R2-S3, 20.2R3; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R1-S1, 20.4R2. This issue does not affect Juniper Networks Junos OS prior to version 17.2R1 on PTX1000 System. This issue affects Juniper Networks Junos OS on PTX10002-60C System: 18.2 versions 18.2R1 and later versions prior to 18.4 versions prior to 18.4R3-S9; 19.1 versions later than 19.1R1 prior to 19.4 versions prior to 19.4R2-S5, 19.4R3-S5; 20.1 versions prior to 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions 20.4R1 and later versions prior to 21.1 versions prior to 21.1R2; 21.2 versions 21.2R1 and later versions prior to 21.3 versions prior to 21.3R2. This issue does not affect Juniper Networks Junos OS prior to version 18.2R1 on PTX10002-60C System. This issue impacts all filter families (inet, inet6, etc.) and all loopback filters. It does not rely upon the location where a filter is set, impacting both logical and physical interfaces.

Timeline

Scores

EPSS (exploitation in 30 days)

0.60% · top 51% of all CVEs (7 Nov 2026)

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.

Weakness

• CWE-362 Race Condition (Concurrent Execution using Shared Resource with Improper Synchronization) (opens in a new tab)All about CWE-362 and its CVEs

Affected products

• Juniper Networks · Junos OS

  • unaffected unspecified – < 17.2R1
  • affected 17.2R1 – < 17.2*
  • affected 17.3 – < 17.3R3-S12
  • affected 17.4 – < 17.4R3-S5
  • affected 18.1 – < 18.1R3-S13
  • affected 18.2 – < 18.2R3-S8
  • affected 18.3 – < 18.3R3-S5
  • affected 18.4 – < 18.4R1-S8, 18.4R2-S8, 18.4R3-S8
  • affected 19.1 – < 19.1R3-S5
  • affected 19.2 – < 19.2R3-S2
  • affected 19.3 – < 19.3R2-S6, 19.3R3-S3
  • affected 19.4 – < 19.4R2-S4, 19.4R3-S3
  • affected 20.1 – < 20.1R3
  • affected 20.2 – < 20.2R2-S3, 20.2R3
  • affected 20.3 – < 20.3R2-S1, 20.3R3
  • affected 20.4 – < 20.4R1-S1, 20.4R2

• Juniper Networks · Junos OS

  • affected 18.4 – < 18.4R3-S9
  • affected 19.1R1 – < 19.1*
  • affected 19.4 – < 19.4R2-S5, 19.4R3-S5
  • affected 20.1 – < 20.1R3-S1
  • affected 20.2 – < 20.2R3-S2
  • affected 20.3 – < 20.3R3-S1
  • affected 20.4R1 – < 20.4*
  • affected 21.1 – < 21.1R2
  • affected 21.2R1 – < 21.2*
  • affected 21.3 – < 21.3R2
  • unaffected 18.2 – < 18.2R1

What to do

Solution: The following software releases have been updated to resolve this specific issue: Junos OS on PTX1000 System: 17.3R3-S12, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R1-S8, 18.4R2-S8, 18.4R3-S8, 19.1R3-S5, 19.2R3-S2, 19.3R2-S6, 19.3R3-S3, 19.4R2-S4, 19.4R3-S3, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2-S1, 20.3R3, 20.4R1-S1, 20.4R2, 21.1R1, and all subsequent releases. Junos OS on PTX10002-60C System: 18.4R3-S9, 19.4R2-S5, 19.4R3-S5, 20.1R3-S1, 20.2R3-S2, 20.3R3-S1, 21.1R2, 21.3R2, 21.4R1, and all subsequent releases.

Workaround: Restart the firewall daemon after the system has rebooted after the upgrade.

Exploitation: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

References (2)

• https://kb.juniper.net/JSA11250 (opens in a new tab)x_refsource_CONFIRMx_transferred
• https://kb.juniper.net/KB10956 (opens in a new tab)x_refsource_MISCx_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2021-31382](https://trackcve.app/badge/CVE-2021-31382.svg)](https://trackcve.app/cve/CVE-2021-31382)

Record last updated 17 Sept 2024, 01:05 UTC.