CVE-2021-0219Public exploit

Root command execution via unquoted package path

Published Jan 15, 2021 · Updated Sep 16, 2024

OS command injection in the package validator of Juniper Networks Junos OS allows local users with maintenance privilege to execute commands as root. The mgd_package_real path passes the attacker-controlled package filename into a tar command built with snprintf and opened by popen after checking only that the file exists. Access to the request system software add validate-on-host CLI operation is required, and successful injection grants root-level command execution on the network device.

CVSS severity6.7
Medium
EPSS probability0.70%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

OS command injection in the package validator of Juniper Networks Junos OS allows local users with maintenance privilege to execute commands as root. The mgd_package_real path passes the attacker-controlled package filename into a tar command built with snprintf and opened by popen after checking only that the file exists. Access to the request system software add validate-on-host CLI operation is required, and successful injection grants root-level command execution on the network device.

The record

CVE
CVE-2021-0219
Published
Jan 15, 2021
Updated
Sep 16, 2024
Vendor
Juniper Networks
Product
Junos OS
Classifications
CWE-78, T1059.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=17.4 <17.4R2-S12, 17.4R3-S3
  2. Affected versionversion=18.1 <18.1R3-S11
  3. Affected versionversion=18.2 <18.2R2-S8, 18.2R3-S6
  4. Affected versionversion=18.3 <18.3R3-S4
  5. Affected versionversion=18.4 <18.4R1-S8, 18.4R2-S7, 18.4R3-S6
  6. Affected versionversion=19.1 <19.1R1-S6, 19.1R2-S2, 19.1R3-S3
  7. Affected versionversion=19.2 <19.2R3-S1
  8. Affected versionversion=19.3 <19.3R2-S5, 19.3R3-S1
  9. Affected versionversion=19.4 <19.4R2-S2, 19.4R3-S1
  10. Affected versionversion=20.1 <20.1R2
  11. Affected versionversion=20.2 <20.2R1-S2, 20.2R2
  12. Affected versionversion=20.3 <20.3R1-S1, 20.3R2
  13. Affected versionversion=unspecified <17.3R3-S10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Juniper Networks · Junos OSversion=17.4 <17.4R2-S12, 17.4R3-S3; version=18.1 <18.1R3-S11; version=18.2 <18.2R2-S8, 18.2R3-S6; version=18.3 <18.3R3-S4; version=18.4 <18.4R1-S8, 18.4R2-S7, 18.4R3-S6; version=19.1 <19.1R1-S6, 19.1R2-S2, 19.1R3-S3; version=19.2 <19.2R3-S1; version=19.3 <19.3R2-S5, 19.3R3-S1; version=19.4 <19.4R2-S2, 19.4R3-S1; version=20.1 <20.1R2; version=20.2 <20.2R1-S2, 20.2R2; version=20.3 <20.3R1-S1, 20.3R2; version=unspecified <17.3R3-S10

Published CVSS scores

6.7Juniper NetworksCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
7.2NIST NVDAV:L/AC:L/Au:N/C:C/I:C/A:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-78Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
T1059.004Command and Scripting Interpreter: Unix Shell

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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