CVE detail

CVE-2021-0223 — CVE-2021-0223

Published 2021-01-15 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
HIGH
severity
CVSS-derived band
7.8
CVSS v3
0–10 scale
0.0038
EPSS probability
exploitation probability, 30d
31.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

A local privilege escalation vulnerability in telnetd.real of Juniper Networks Junos OS may allow a locally authenticated shell user to escalate privileges and execute arbitrary commands as root. telnetd.real is shipped with setuid permissions enabled and is owned by the root user, allowing local users to run telnetd.real with root privileges. This issue affects Juniper Networks Junos OS: all versions prior to 15.1R7-S9; 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S12, 17.4R3-S3; 18.1 versions prior to 18.1R3-S11; 18.2 versions prior to 18.2R3-S6; 18.3 versions prior to 18.3R2-S4, 18.3R3-S4; 18.4 versions prior to 18.4R2-S7, 18.4R3-S6; 19.1 versions prior to 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S1; 19.3 versions prior to 19.3R3-S1; 19.4 versio

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: Junos OS 15.1R7-S9*, 17.3R3-S11*, 17.4R2-S12, 17.4R3-S3, 18.1R3-S11, 18.2R3-S6, 18.3R2-S4, 18.3R3-S4, 18.4R2-S7, 18.4R3-S6, 19.1R2-S2, 19.1R3-S4, 19.2R1-S6, 19.2R3-S1, 19.3R3-S1, 19.4R2-S2, 19.4R3, 20.1R1-S4, 20.1R2, 20.2R2, 20.3R1, and all subsequent releases. *Late availability

workarounds

Use access lists or firewall filters to limit CLI access to the device only from trusted, administrative networks or hosts. Limit access to the Junos OS shell to only trusted system administrators.

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=unspecified<15.1R7-S915.1R7-S9advisory ↗
Juniper Networks Junos OS>=17.3<17.3R3-S1117.3R3-S11advisory ↗
Juniper Networks Junos OS>=17.4<17.4R2-S12, 17.4R3-S317.4R2-S12, 17.4R3-S3advisory ↗
Juniper Networks Junos OS>=18.1<18.1R3-S1118.1R3-S11advisory ↗
Juniper Networks Junos OS>=18.2<18.2R3-S618.2R3-S6advisory ↗
Juniper Networks Junos OS>=18.3<18.3R2-S4, 18.3R3-S418.3R2-S4, 18.3R3-S4advisory ↗
Juniper Networks Junos OS>=18.4<18.4R2-S7, 18.4R3-S618.4R2-S7, 18.4R3-S6advisory ↗
Juniper Networks Junos OS>=19.1<19.1R2-S2, 19.1R3-S419.1R2-S2, 19.1R3-S4advisory ↗
Juniper Networks Junos OS>=19.2<19.2R1-S6, 19.2R3-S119.2R1-S6, 19.2R3-S1advisory ↗
Juniper Networks Junos OS>=19.3<19.3R3-S119.3R3-S1advisory ↗
Juniper Networks Junos OS>=19.4<19.4R2-S2, 19.4R319.4R2-S2, 19.4R3advisory ↗
Juniper Networks Junos OS>=20.1<20.1R1-S4, 20.1R220.1R1-S4, 20.1R2advisory ↗
Juniper Networks Junos OS>=20.2<20.2R220.2R2advisory ↗

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.