CVE-2021-0253 Junos OS: NFX Series: Local Command Execution Vulnerability in JDMD Leads to Privilege Escalation
Local attackers can execute arbitrary commands via JDMD to escalate privileges on Juniper NFX Series devices running Junos OS.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-0253?
CVE-2021-0253 is a high-severity command injection vulnerability in Juniper Junos, published on 22 Apr 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
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.
Weakness: CWE-77
Which versions are affected by CVE-2021-0253?
It affects 1 product.
Products include Juniper Junos.
How do I fix CVE-2021-0253?
No fix has been published for CVE-2021-0253 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2021-0253 being exploited?
There is no known exploitation of CVE-2021-0253 in the wild and no public exploit code.
Other vulnerabilities in Juniper Junos
- CVE-2023-36845 Juniper Junos OS EX Series and SRX Series PHP External Variable Modification
- CVE-2020-1631 Juniper Junos OS Path Traversal
- CVE-2025-21590 Juniper Junos OS Improper Isolation or Compartmentalization
- CVE-2023-36851 Juniper Junos OS SRX Series Missing Authentication for Critical Function
- CVE-2023-36844 Juniper Junos OS EX Series PHP External Variable Modification
Sources
Also known as GHSA-8mfm-9h94-j57q.