CVE-2021-31382 json
Junos OS: PTX1000 System, PTX10002-60C System: After upgrading, configured firewall filters may be applied on incorrect interfaces
published 2021-10-19 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-18292
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.6%
- EPSS 0.6% chance of exploitation in 30 days, percentile 49%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- Juniper Networks Junos OS 17.3R3-S12, 17.4R3-S5, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R1-S8, 18.4R2-S8, 18.4R3-S8, 18.4R3-S9, 19.1R3-S5, 19.2R3-S2, 19.3R2-S6, 19.3R3-S3, 19.4R2-S4, 19.4R3-S3, 19.4R2-S5, 19.4R3-S5, 20.1R3, 20.1R3-S1, 20.2R2-S3, 20.2R3, 20.2R3-S2, 20.3R2-S1, 20.3R3, 20.3R3-S1, 20.4R1-S1, 20.4R2, 21.1R2
Exploit prediction
0.60% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:L |
| NVD | 3.1 | 9.0 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVD | 2.0 | 6.8 | AV:N/AC:M/Au:N/C:P/I:P/A:P |
Affected products
- Juniper Networks Junos OS
Classification
- Weakness
-
- CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
References
-
kb.juniper.net
/JSA11250
vendor-advisory
-
kb.juniper.net
/KB10956
vendor-advisory
Sources
- CVE List CVE-2021-31382
- NVD CVE-2021-31382
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