CVE detail

CVE-2021-0291 — CVE-2021-0291

Published 2021-07-15 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
MEDIUM
severity
CVSS-derived band
6.5
CVSS v3
0–10 scale
0.0101
EPSS probability
exploitation probability, 30d
60.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

An Exposure of System Data vulnerability in Juniper Networks Junos OS and Junos OS Evolved, where a sensitive system-level resource is not being sufficiently protected, allows a network-based unauthenticated attacker to send specific traffic which partially reaches this resource. A high rate of specific traffic may lead to a partial Denial of Service (DoS) as the CPU utilization of the RE is significantly increased. The SNMP Agent Extensibility (agentx) process should only be listening to TCP port 705 on the internal routing instance. External connections destined to port 705 should not be allowed. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R2-S13, 17.4R3-S5; 18.3 versions prior to 18.3R3-S5

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: Junos OS: 15.1R7-S9, 17.3R3-S12, 17.4R2-S13, 17.4R3-S5, 18.3R3-S5, 18.4R2-S8, 19.1R3-S5, 19.2R3-S2, 19.3R2-S6, 19.3R3-S2, 19.4R1-S4, 19.4R2-S4, 19.4R3, 20.1R2, 20.2R2, 20.2R3, 20.3R2, 20.4R1, and all subsequent releases. Junos OS Evolved: 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.

workarounds

Use access lists or firewall filters to deny access to TCP port 705.

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=15.1<15.1R7-S915.1R7-S9advisory ↗
Juniper Networks Junos OS>=17.3<17.3R3-S1217.3R3-S12advisory ↗
Juniper Networks Junos OS>=17.4<17.4R2-S13, 17.4R3-S517.4R2-S13, 17.4R3-S5advisory ↗
Juniper Networks Junos OS>=18.3<18.3R3-S518.3R3-S5advisory ↗
Juniper Networks Junos OS>=18.4<18.4R2-S8, 18.4R3-S918.4R2-S8, 18.4R3-S9advisory ↗
Juniper Networks Junos OS>=19.1<19.1R3-S519.1R3-S5advisory ↗
Juniper Networks Junos OS>=19.2<19.2R3-S219.2R3-S2advisory ↗
Juniper Networks Junos OS>=19.3<19.3R2-S6, 19.3R3-S219.3R2-S6, 19.3R3-S2advisory ↗
Juniper Networks Junos OS>=19.4<19.4R1-S4, 19.4R2-S4, 19.4R319.4R1-S4, 19.4R2-S4, 19.4R3advisory ↗
Juniper Networks Junos OS>=20.1<20.1R220.1R2advisory ↗
Juniper Networks Junos OS>=20.2<20.2R220.2R2advisory ↗
Juniper Networks Junos OS>=20.3<20.3R220.3R2advisory ↗
Juniper Networks Junos OS Evolved>=unspecified<20.3R2-EVO20.3R2-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.