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2021-04 Security Bulletin: Junos OS: NFX Series: Local Command Execution Vulnerability in JDMD Leads to Privilege Escalation (CVE-2021-0253)



Article ID: JSA11146 SECURITY_ADVISORIES Last Updated: 14 Apr 2021Version: 3.0
Product Affected:
This issue affects Junos OS. 17.2R1 and later versions prior to 18.3R3-S4, 18.4, 19.1, 19.2, 19.3, 19.4. Affected platforms: NFX Series.

NFX Series devices using Juniper Networks Junos OS are susceptible to a local command execution vulnerability thereby allowing an attacker to elevate their privileges via the Junos Device Management Daemon (JDMD) process.

This issue affects Juniper Networks Junos OS on NFX Series:

  • 17.2 version 17.2R1 and later versions prior to 18.3R3-S4;
  • 18.4 versions prior to 18.4R2-S5, 18.4R3-S5;
  • 19.1 versions prior to 19.1R1-S3;
  • 19.2 version 19.1R2 and later versions prior to 19.2R3;
  • 19.3 versions prior to 19.3R3;
  • 19.4 versions prior to 19.4R2-S2.
  • 19.4 versions 19.4R3 and above.
  • This issue does not affect Juniper Networks Junos OS versions prior to 17.2R1.

This issue does not affect the JDMD as used by Junos Node Slicing such as External Servers use in conjunction with Junos Node Slicing and In-Chassis Junos Node Slicing on MX480, MX960, MX2008, MX2010, MX2020.

There is no specific software configuration required to be affected by this issue on affected platforms and products.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was discovered during a external security research.

This issue has been assigned CVE-2021-0253.


The following software releases have been updated to resolve this specific issue: 18.3R3-S4, 18.4R2-S5, 18.4R3-S5, 19.1R3-S3, 19.2R3, 19.3R3, 19.4R2-S2, 20.1R1 and all subsequent releases.

This issue is being tracked as 1452431.


There are no viable workarounds for this issue.

To reduce the risk of exploitation of this issue, use access lists or firewall filters to limit access to only trusted administrative networks, hosts and users.

Software releases or updates are available for download at
Modification History:
2021-04-14: Initial Publication.
CVSS Score:
7.8 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."
  • Cyrille CHATRAS from Orange group

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