Vulnerability Database

346,508

Total vulnerabilities in the database

CVE-2021-31382 — juniper / junos

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

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.

  • Published: Oct 19, 2021
  • Updated: Nov 16, 2025
  • CVE: CVE-2021-31382
  • Severity: Medium
  • Exploit:

CVSS v3:

  • Severity: Medium
  • Score: 6.5
  • AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L

CVSS v2:

  • Severity: Medium
  • Score: 6.8
  • AV:N/AC:M/Au:N/C:P/I:P/A:P

CWEs:

Software From Fixed in
juniper / junos 17.2-r1 17.2-r1.x
juniper / junos 17.2-r2 17.2-r2.x
juniper / junos 17.2-r1-s2 17.2-r1-s2.x
juniper / junos 17.2-r3 17.2-r3.x
juniper / junos 17.2-r2-s4 17.2-r2-s4.x
juniper / junos 17.2-r1-s6 17.2-r1-s6.x
juniper / junos 17.2-r1-s1 17.2-r1-s1.x
juniper / junos 17.2-r1-s3 17.2-r1-s3.x
juniper / junos 17.2-r1-s5 17.2-r1-s5.x
juniper / junos 17.2-r1-s7 17.2-r1-s7.x
juniper / junos 17.2-r1-s4 17.2-r1-s4.x
juniper / junos 17.2-r2-s6 17.2-r2-s6.x
juniper / junos 17.2-r2-s7 17.2-r2-s7.x
juniper / junos 17.2-r3-s1 17.2-r3-s1.x
juniper / junos 17.2-r1-s8 17.2-r1-s8.x
juniper / junos 17.2-r3-s2 17.2-r3-s2.x
juniper / junos 17.2-r2-s11 17.2-r2-s11.x
juniper / junos 17.2-r3-s3 17.2-r3-s3.x
juniper / junos 17.2-r3-s4 17.2-r3-s4.x
juniper / junos 17.2x75 17.2x75.x
juniper / junos 17.2x75-d91 17.2x75-d91.x
juniper / junos 17.2x75-d92 17.2x75-d92.x
juniper / junos 17.2x75-d70 17.2x75-d70.x
juniper / junos 17.2x75-d102 17.2x75-d102.x
juniper / junos 17.2x75-d100 17.2x75-d100.x
juniper / junos 17.2x75-d90 17.2x75-d90.x
juniper / junos 17.2x75-d110 17.2x75-d110.x
juniper / junos 17.2x75-d50 17.2x75-d50.x
juniper / junos 17.3-r1 17.3-r1.x
juniper / junos 17.3-r2 17.3-r2.x
juniper / junos 17.3-r2-s2 17.3-r2-s2.x
juniper / junos 17.3-r3 17.3-r3.x
juniper / junos 17.3-r1-s4 17.3-r1-s4.x
juniper / junos 17.3-r3-s1 17.3-r3-s1.x
juniper / junos 17.3-r3-s2 17.3-r3-s2.x
juniper / junos 17.3-r2-s1 17.3-r2-s1.x
juniper / junos 17.3 17.3.x
juniper / junos 17.3-r3-s3 17.3-r3-s3.x
juniper / junos 17.3-r3-s4 17.3-r3-s4.x
juniper / junos 17.3-r3-s5 17.3-r3-s5.x
juniper / junos 17.3-r2-s4 17.3-r2-s4.x
juniper / junos 17.3-r1-s1 17.3-r1-s1.x
juniper / junos 17.3-r2-s3 17.3-r2-s3.x
juniper / junos 17.3-r3-s6 17.3-r3-s6.x
juniper / junos 17.3-r3-s7 17.3-r3-s7.x
juniper / junos 17.3-r2-s5 17.3-r2-s5.x
juniper / junos 17.3-r3-s11 17.3-r3-s11.x
juniper / junos 17.3-r3-s9 17.3-r3-s9.x
juniper / junos 17.3-r3-s10 17.3-r3-s10.x
juniper / junos 17.3-r3-s8 17.3-r3-s8.x
juniper / junos 17.4-r2-s11 17.4-r2-s11.x
juniper / junos 17.4-r3-s2 17.4-r3-s2.x
juniper / junos 17.4-r3-s3 17.4-r3-s3.x
juniper / junos 17.4-r3-s4 17.4-r3-s4.x
juniper / junos 17.4-r2-s12 17.4-r2-s12.x
juniper / junos 17.4-r2-s13 17.4-r2-s13.x
juniper / junos 17.4-r3-s1 17.4-r3-s1.x
juniper / junos 17.4-r2-s9 17.4-r2-s9.x
juniper / junos 17.4-r2-s10 17.4-r2-s10.x
juniper / junos 17.4-r2-s5 17.4-r2-s5.x
juniper / junos 17.4-r2-s6 17.4-r2-s6.x
juniper / junos 17.4-r2-s7 17.4-r2-s7.x
juniper / junos 17.4-r2-s8 17.4-r2-s8.x
juniper / junos 17.4-r2-s3 17.4-r2-s3.x
juniper / junos 17.4-r2-s4 17.4-r2-s4.x
juniper / junos 17.4-r1-s6 17.4-r1-s6.x
juniper / junos 17.4-r1-s5 17.4-r1-s5.x
juniper / junos 17.4-r1-s7 17.4-r1-s7.x
juniper / junos 17.4-r1-s4 17.4-r1-s4.x
juniper / junos 17.4 17.4.x
juniper / junos 17.4-r3 17.4-r3.x
juniper / junos 17.4-r2-s1 17.4-r2-s1.x
juniper / junos 17.4-r1-s2 17.4-r1-s2.x
juniper / junos 17.4-r2-s2 17.4-r2-s2.x
juniper / junos 17.4-r1-s1 17.4-r1-s1.x
juniper / junos 17.4-r1-s3 17.4-r1-s3.x
juniper / junos 17.4-r1 17.4-r1.x
juniper / junos 17.4-r2 17.4-r2.x
juniper / junos 18.1-r2 18.1-r2.x
juniper / junos 18.1-r1 18.1-r1.x
juniper / junos 18.1-r3 18.1-r3.x
juniper / junos 18.1-r2-s2 18.1-r2-s2.x
juniper / junos 18.1-r3-s4 18.1-r3-s4.x
juniper / junos 18.1-r3-s3 18.1-r3-s3.x
juniper / junos 18.1-r3-s2 18.1-r3-s2.x
juniper / junos 18.1 18.1.x
juniper / junos 18.1-r2-s1 18.1-r2-s1.x
juniper / junos 18.1-r2-s4 18.1-r2-s4.x
juniper / junos 18.1-r3-s1 18.1-r3-s1.x
juniper / junos 18.1-r3-s5 18.1-r3-s5.x
juniper / junos 18.1-r3-s6 18.1-r3-s6.x
juniper / junos 18.1-r3-s7 18.1-r3-s7.x
juniper / junos 18.1-r3-s9 18.1-r3-s9.x
juniper / junos 18.1-r3-s8 18.1-r3-s8.x
juniper / junos 18.1-r 18.1-r.x
juniper / junos 18.1-r3-s12 18.1-r3-s12.x
juniper / junos 18.1-r3-s11 18.1-r3-s11.x
juniper / junos 18.1-r3-s10 18.1-r3-s10.x
juniper / junos 18.2-r3-s5 18.2-r3-s5.x
juniper / junos 18.2-r3-s3 18.2-r3-s3.x
juniper / junos 18.2-r3-s4 18.2-r3-s4.x
juniper / junos 18.2-r3-s6 18.2-r3-s6.x
juniper / junos 18.2-r1-s2 18.2-r1-s2.x
juniper / junos 18.2-r2-s7 18.2-r2-s7.x
juniper / junos 18.2-r3-s7 18.2-r3-s7.x
juniper / junos 18.2-r2-s8 18.2-r2-s8.x
juniper / junos 18.2-r3-s2 18.2-r3-s2.x
juniper / junos 18.2-r1-s4 18.2-r1-s4.x
juniper / junos 18.2-r1-s5 18.2-r1-s5.x
juniper / junos 18.2-r2 18.2-r2.x
juniper / junos 18.2-r3-s1 18.2-r3-s1.x
juniper / junos 18.2-r3 18.2-r3.x
juniper / junos 18.2-r2-s5 18.2-r2-s5.x
juniper / junos 18.2-r2-s6 18.2-r2-s6.x
juniper / junos 18.2-r2-s3 18.2-r2-s3.x
juniper / junos 18.2-r2-s4 18.2-r2-s4.x
juniper / junos 18.2-r1 18.2-r1.x
juniper / junos 18.2 18.2.x
juniper / junos 18.2-r2-s1 18.2-r2-s1.x
juniper / junos 18.2-r2-s2 18.2-r2-s2.x
juniper / junos 18.2-r1-s3 18.2-r1-s3.x
juniper / junos 18.3-r1-s1 18.3-r1-s1.x
juniper / junos 18.3-r1-s3 18.3-r1-s3.x
juniper / junos 18.3-r1-s2 18.3-r1-s2.x
juniper / junos 18.3 18.3.x
juniper / junos 18.3-r2 18.3-r2.x
juniper / junos 18.3-r1 18.3-r1.x
juniper / junos 18.3-r1-s5 18.3-r1-s5.x
juniper / junos 18.3-r2-s1 18.3-r2-s1.x
juniper / junos 18.3-r2-s2 18.3-r2-s2.x
juniper / junos 18.3-r1-s4 18.3-r1-s4.x
juniper / junos 18.3-r3 18.3-r3.x
juniper / junos 18.3-r1-s6 18.3-r1-s6.x
juniper / junos 18.3-r3-s1 18.3-r3-s1.x
juniper / junos 18.3-r2-s3 18.3-r2-s3.x
juniper / junos 18.3-r 18.3-r.x
juniper / junos 18.3-r3-s4 18.3-r3-s4.x
juniper / junos 18.3-r3-s2 18.3-r3-s2.x
juniper / junos 18.3-r2-s4 18.3-r2-s4.x
juniper / junos 18.3-r3-s3 18.3-r3-s3.x
juniper / junos 18.4-r3-s5 18.4-r3-s5.x
juniper / junos 18.4-r2-s5 18.4-r2-s5.x
juniper / junos 18.4-r2-s6 18.4-r2-s6.x
juniper / junos 18.4-r3-s3 18.4-r3-s3.x
juniper / junos 18.4-r3-s4 18.4-r3-s4.x
juniper / junos 18.4-r3-s6 18.4-r3-s6.x
juniper / junos 18.4-r1-s7 18.4-r1-s7.x
juniper / junos 18.4-r3-s7 18.4-r3-s7.x
juniper / junos 18.4-r2-s7 18.4-r2-s7.x
juniper / junos 18.4-r1-s6 18.4-r1-s6.x
juniper / junos 18.4-r3-s2 18.4-r3-s2.x
juniper / junos 18.4-r3-s1 18.4-r3-s1.x
juniper / junos 18.4-r2-s4 18.4-r2-s4.x
juniper / junos 18.4-r3 18.4-r3.x
juniper / junos 18.4-r2-s3 18.4-r2-s3.x
juniper / junos 18.4-r2-s2 18.4-r2-s2.x
juniper / junos 18.4-r1-s3 18.4-r1-s3.x
juniper / junos 18.4-r1-s4 18.4-r1-s4.x
juniper / junos 18.4-r1-s2 18.4-r1-s2.x
juniper / junos 18.4-r2-s1 18.4-r2-s1.x
juniper / junos 18.4-r2 18.4-r2.x
juniper / junos 18.4-r1-s5 18.4-r1-s5.x
juniper / junos 18.4-r1 18.4-r1.x
juniper / junos 18.4 18.4.x
juniper / junos 18.4-r1-s1 18.4-r1-s1.x
juniper / junos 19.1-r1 19.1-r1.x
juniper / junos 19.1 19.1.x
juniper / junos 19.1-r1-s1 19.1-r1-s1.x
juniper / junos 19.1-r1-s3 19.1-r1-s3.x
juniper / junos 19.1-r1-s2 19.1-r1-s2.x
juniper / junos 19.1-r2 19.1-r2.x
juniper / junos 19.1-r2-s1 19.1-r2-s1.x
juniper / junos 19.1-r3 19.1-r3.x
juniper / junos 19.1-r3-s1 19.1-r3-s1.x
juniper / junos 19.1-r1-s4 19.1-r1-s4.x
juniper / junos 19.1-r1-s6 19.1-r1-s6.x
juniper / junos 19.1-r2-s3 19.1-r2-s3.x
juniper / junos 19.1-r2-s2 19.1-r2-s2.x
juniper / junos 19.1-r1-s5 19.1-r1-s5.x
juniper / junos 19.1-r3-s4 19.1-r3-s4.x
juniper / junos 19.1-r3-s2 19.1-r3-s2.x
juniper / junos 19.1-r3-s3 19.1-r3-s3.x
juniper / junos 19.2-r1-s5 19.2-r1-s5.x
juniper / junos 19.2-r3 19.2-r3.x
juniper / junos 19.2-r2 19.2-r2.x
juniper / junos 19.2-r3-s1 19.2-r3-s1.x
juniper / junos 19.2-r2-s1 19.2-r2-s1.x
juniper / junos 19.2-r1-s6 19.2-r1-s6.x
juniper / junos 19.2-r1-s7 19.2-r1-s7.x
juniper / junos 19.2-r1-s4 19.2-r1-s4.x
juniper / junos 19.2-r1-s3 19.2-r1-s3.x
juniper / junos 19.2-r1 19.2-r1.x
juniper / junos 19.2-r1-s1 19.2-r1-s1.x
juniper / junos 19.2-r1-s2 19.2-r1-s2.x
juniper / junos 19.2 19.2.x
juniper / junos 19.3 19.3.x
juniper / junos 19.3-r1 19.3-r1.x
juniper / junos 19.3-r2 19.3-r2.x
juniper / junos 19.3-r2-s1 19.3-r2-s1.x
juniper / junos 19.3-r1-s1 19.3-r1-s1.x
juniper / junos 19.3-r2-s2 19.3-r2-s2.x
juniper / junos 19.3-r3-s2 19.3-r3-s2.x
juniper / junos 19.3-r3-s1 19.3-r3-s1.x
juniper / junos 19.3-r2-s3 19.3-r2-s3.x
juniper / junos 19.3-r2-s4 19.3-r2-s4.x
juniper / junos 19.3-r2-s5 19.3-r2-s5.x
juniper / junos 19.3-r3 19.3-r3.x
juniper / junos 19.4-r3 19.4-r3.x
juniper / junos 19.4-r2-s2 19.4-r2-s2.x
juniper / junos 19.4-r2 19.4-r2.x
juniper / junos 19.4-r2-s1 19.4-r2-s1.x
juniper / junos 19.4-r1-s3 19.4-r1-s3.x
juniper / junos 19.4-r3-s1 19.4-r3-s1.x
juniper / junos 19.4-r2-s3 19.4-r2-s3.x
juniper / junos 19.4-r1-s4 19.4-r1-s4.x
juniper / junos 19.4-r3-s2 19.4-r3-s2.x
juniper / junos 19.4-r1-s1 19.4-r1-s1.x
juniper / junos 19.4-r1-s2 19.4-r1-s2.x
juniper / junos 19.4-r1 19.4-r1.x
juniper / junos 20.1-r1 20.1-r1.x
juniper / junos 20.1-r1-s1 20.1-r1-s1.x
juniper / junos 20.1-r2-s2 20.1-r2-s2.x
juniper / junos 20.1-r2 20.1-r2.x
juniper / junos 20.1-r2-s1 20.1-r2-s1.x
juniper / junos 20.1-r1-s4 20.1-r1-s4.x
juniper / junos 20.1-r1-s2 20.1-r1-s2.x
juniper / junos 20.1-r1-s3 20.1-r1-s3.x
juniper / junos 20.2-r1 20.2-r1.x
juniper / junos 20.2-r1-s1 20.2-r1-s1.x
juniper / junos 20.2-r1-s2 20.2-r1-s2.x
juniper / junos 20.2-r1-s3 20.2-r1-s3.x
juniper / junos 20.2-r2-s2 20.2-r2-s2.x
juniper / junos 20.2-r2 20.2-r2.x
juniper / junos 20.2-r2-s1 20.2-r2-s1.x
juniper / junos 20.3-r1-s1 20.3-r1-s1.x
juniper / junos 20.3-r1 20.3-r1.x
juniper / junos 20.3-r2 20.3-r2.x
juniper / junos 20.4-r1 20.4-r1.x
juniper / junos 18.2x75-d60 18.2x75-d60.x
juniper / junos 18.2x75-d50 18.2x75-d50.x
juniper / junos 18.2x75-d12 18.2x75-d12.x
juniper / junos 18.2x75-d51 18.2x75-d51.x
juniper / junos 18.2x75-d411 18.2x75-d411.x
juniper / junos 18.2x75-d30 18.2x75-d30.x
juniper / junos 18.2x75-d40 18.2x75-d40.x
juniper / junos 18.2x75 18.2x75.x
juniper / junos 18.2x75-d5 18.2x75-d5.x
juniper / junos 18.2x75-d20 18.2x75-d20.x
juniper / junos 18.2x75-d10 18.2x75-d10.x
juniper / junos 18.4-r3-s8 18.4-r3-s8.x
juniper / junos 19.4-r3-s3 19.4-r3-s3.x
juniper / junos 19.4-r3-s4 19.4-r3-s4.x
juniper / junos 19.4-r2-s4 19.4-r2-s4.x
juniper / junos 20.1-r3 20.1-r3.x
juniper / junos 20.2-r2-s3 20.2-r2-s3.x
juniper / junos 20.2-r3 20.2-r3.x
juniper / junos 20.2-r3-s1 20.2-r3-s1.x
juniper / junos 20.3-r2-s1 20.3-r2-s1.x
juniper / junos 20.3-r3 20.3-r3.x
juniper / junos 20.4-r3 20.4-r3.x
juniper / junos 20.4-r2-s1 20.4-r2-s1.x
juniper / junos 20.4-r1-s1 20.4-r1-s1.x
juniper / junos 20.4-r2 20.4-r2.x
juniper / junos 21.1-r1 21.1-r1.x
juniper / junos 21.1-r1-s1 21.1-r1-s1.x
juniper / junos 21.2-r1 21.2-r1.x
juniper / junos 21.2-r1-s1 21.2-r1-s1.x
juniper / junos 21.2-r2 21.2-r2.x
juniper / junos 21.3-r1 21.3-r1.x

Frequently Asked Questions

A security vulnerability is a weakness in software, hardware, or configuration that can be exploited to compromise confidentiality, integrity, or availability. Many vulnerabilities are tracked as CVEs (Common Vulnerabilities and Exposures), which provide a standardized identifier so teams can coordinate patching, mitigation, and risk assessment across tools and vendors.

CVSS (Common Vulnerability Scoring System) estimates technical severity, but it doesn't automatically equal business risk. Prioritize using context like internet exposure, affected asset criticality, known exploitation (proof-of-concept or in-the-wild), and whether compensating controls exist. A "Medium" CVSS on an exposed, production system can be more urgent than a "Critical" on an isolated, non-production host.

A vulnerability is the underlying weakness. An exploit is the method or code used to take advantage of it. A zero-day is a vulnerability that is unknown to the vendor or has no publicly available fix when attackers begin using it. In practice, risk increases sharply when exploitation becomes reliable or widespread.

Recurring findings usually come from incomplete Asset Discovery, inconsistent patch management, inherited images, and configuration drift. In modern environments, you also need to watch the software supply chain: dependencies, containers, build pipelines, and third-party services can reintroduce the same weakness even after you patch a single host. Unknown or unmanaged assets (often called Shadow IT) are a common reason the same issues resurface.

Use a simple, repeatable triage model: focus first on externally exposed assets, high-value systems (identity, VPN, email, production), vulnerabilities with known exploits, and issues that enable remote code execution or privilege escalation. Then enforce patch SLAs and track progress using consistent metrics so remediation is steady, not reactive.

SynScan combines attack surface monitoring and continuous security auditing to keep your inventory current, flag high-impact vulnerabilities early, and help you turn raw findings into a practical remediation plan.