CVE detail

CVE-2021-0273 — CVE-2021-0273

Published 2021-04-22 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
MEDIUM
severity
CVSS-derived band
5.3
CVSS v3
0–10 scale
0.0100
EPSS probability
exploitation probability, 30d
60.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

An always-incorrect control flow implementation in the implicit filter terms of Juniper Networks Junos OS and Junos OS Evolved on ACX5800, EX9200 Series, MX10000 Series, MX240, MX480, MX960 devices with affected Trio line cards allows an attacker to exploit an interdependency in the PFE UCODE microcode of the Trio chipset with various line cards to cause packets destined to the devices interfaces to cause a Denial of Service (DoS) condition by looping the packet with an unreachable exit condition ('Infinite Loop'). To break this loop once it begins one side of the affected LT interfaces will need to be disabled. Once disabled, the condition will clear and the disabled LT interface can be reenabled. Continued receipt and processing of these packets will create a sustained Denial of Service

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: Junos OS: 16.1R7-S8, 17.1R2-S12, 17.2R3-S4, 17.3R3-S8, 17.4R2-S10, 17.4R3-S2, 18.1R3-S10, 18.2R2-S7, 18.2R3-S3, 18.3R1-S7, 18.3R3-S2, 18.4R1-S7, 18.4R2-S4, 18.4R3-S2, 19.1R1-S5, 19.1R2-S1, 19.1R3, 19.2R1-S4, 19.2R2, 19.3R2-S3, 19.3R3, 19.4R1-S1, 19.4R2, 20.1R1, and all subsequent releases. Junos OS Evolved: 19.4R2-EVO, 20.1R1-EVO, and all subsequent releases.

workarounds

There are no available workarounds for this issue.

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=15.1F6<15.1*15.1*advisory ↗
Juniper Networks Junos OS>=16.1R1<16.1*16.1*advisory ↗
Juniper Networks Junos OS>=17.1<17.1R2-S1217.1R2-S12advisory ↗
Juniper Networks Junos OS>=17.2<17.2R3-S417.2R3-S4advisory ↗
Juniper Networks Junos OS>=17.3<17.3R3-S817.3R3-S8advisory ↗
Juniper Networks Junos OS>=17.4<17.4R2-S10, 17.4R3-S217.4R2-S10, 17.4R3-S2advisory ↗
Juniper Networks Junos OS>=18.1<18.1R3-S1018.1R3-S10advisory ↗
Juniper Networks Junos OS>=18.2<18.2R2-S7, 18.2R3-S318.2R2-S7, 18.2R3-S3advisory ↗
Juniper Networks Junos OS>=18.3<18.3R1-S7, 18.3R3-S218.3R1-S7, 18.3R3-S2advisory ↗
Juniper Networks Junos OS>=18.4<18.4R1-S7, 18.4R2-S4, 18.4R3-S218.4R1-S7, 18.4R2-S4, 18.4R3-S2advisory ↗
Juniper Networks Junos OS>=19.1<19.1R1-S5, 19.1R2-S1, 19.1R319.1R1-S5, 19.1R2-S1, 19.1R3advisory ↗
Juniper Networks Junos OS>=19.2<19.2R1-S4, 19.2R219.2R1-S4, 19.2R2advisory ↗
Juniper Networks Junos OS>=19.3<19.3R2-S3, 19.3R319.3R2-S3, 19.3R3advisory ↗
Juniper Networks Junos OS>=19.4<19.4R1-S1, 19.4R219.4R1-S1, 19.4R2advisory ↗
Juniper Networks Junos OS Evolved>=19.4<19.4R2-EVO19.4R2-EVOadvisory ↗

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.