01 Record

CVE-2021-0247

Junos OS: PTX Series, QFX Series: Due to a race condition input loopback firewall filters applied to interfaces may not operate even when listed in the running configuration.

MediumPUBLISHEDCNA: juniper

CNA base score5.1 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:L

View raw JSON

02 Description

Junos OS: PTX Series, QFX Series: Due to a race condition input loopback firewall filters applied to interfaces may not operate even when listed in the running configuration.

03 Exploitation and scoring

Exploitation: Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
SSVC decision: Not assessed by CISA
EPSS probability: 0.55% probability of exploitation activity in the next 30 days.
EPSS percentile: Equal to or higher than the score of 46.0% of scored records. A rank, not a probability.
NVD base score: 5.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:L
NVD analysis status: Modified. NVD last modified this record on 2026-06-17.
Red Hat severity: No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published

2021-04-22 19:37Z5 YR AGO

Last updated

2024-09-16 17:27Z2 YR AGO

Reserved

2020-10-27

Assigning CNA

juniper

Record state

PUBLISHED

Severity

Medium (CVSS 5.1)

CNA CVSS vector

CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:L/I:L/A:L

Weaknesses

CWE-362Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')Class

Data version

5.1

Document digest

3d5180fca644d73a9652957cdb84ed0a2c37ffafae4e9e06bc0d244ad5f201ce

05 Affected products

VendorProductVersionsPlatforms

Juniper NetworksJunos OS14.1X53 to < 14.1X53-D53, 15.1X53 to < 15.1X53-D593, 14.1R1 to < 14.1*, 15.1 to < 15.1R7-S6, 16.1 to < 16.1R7-S7, 16.2 to < 16.2R2-S11, 16.2R3, 17.1 to < 17.1R2-S11, 17.1R3-S2, 17.2 to < 17.2R1-S9, 17.2R3-S3, 17.3 to < 17.3R2-S5, 17.3R3-S7, 17.4 to < 17.4R2-S9, 17.4R3, 18.1 to < 18.1R3-S9, 18.2 to < 18.2R2-S6, 18.2R3-S3, 18.3 to < 18.3R1-S7, 18.3R2-S3, 18.3R3-S1, 18.4 to < 18.4R1-S5, 18.4R2-S3, 18.4R3, 19.1 to < 19.1R1-S4, 19.1R2-S1, 19.1R3, 19.2 to < 19.2R1-S3, 19.2R2QFX Series, QFX Series, PTX Series

06 References

kb.juniper.nethttps://kb.juniper.net/JSA11140x_refsource_MISC

07 Remediation

The following software releases have been updated to resolve this specific issue: Junos OS 14.1X53-D53, 15.1R7-S6, 15.1X53-D593, 16.1R7-S7, 16.2R2-S11, 16.2R3, 17.1R2-S11, 17.1R3-S2, 17.2R1-S9, 17.2R3-S3, 17.3R2-S5, 17.3R3-S7, 17.4R2-S9, 17.4R3, 18.1R3-S9, 18.2R2-S6, 18.2R3-S3, 18.3R1-S7, 18.3R2-S3, 18.3R3-S1, 18.4R1-S5, 18.4R2-S3, 18.4R3, 19.1R1-S4, 19.1R2-S1, 19.1R3, 19.2R1-S3, 19.2R2, 19.3R1, and all subsequent releases.