CVE-2021-0218 : Security Advisory and Response

A command injection vulnerability in the license-check daemon of Juniper Networks Junos OS allows a locally authenticated attacker to execute commands with root privilege. This vulnerability affects multiple Junos OS versions.

Understanding CVE-2021-0218

This CVE refers to a command injection vulnerability in Juniper Networks Junos OS, enabling attackers to execute commands with elevated privileges.

What is CVE-2021-0218?

CVE-2021-0218 is a command injection vulnerability in the license-check daemon of Juniper Networks Junos OS, allowing attackers with low privileges to run commands with root privilege.

The Impact of CVE-2021-0218

The vulnerability poses a high impact, with a CVSS base score of 7.8. Attackers can exploit this issue to execute unauthorized commands on affected systems.

Technical Details of CVE-2021-0218

This section covers the specifics of the vulnerability, affected systems, and the exploitation mechanism.

Vulnerability Description

The vulnerability lies in the license-check daemon, enabling authenticated attackers to run commands with elevated privileges.

Affected Systems and Versions

Junos OS versions prior to 20.2R2 are affected, with various releases including 17.3R3-S9, 18.1R3-S11, and 19.4R3 vulnerable to exploitation.

Exploitation Mechanism

An attacker with access to the 'request system license update' CLI command can exploit the vulnerability to execute unauthorized commands with root privilege.

Mitigation and Prevention

To address CVE-2021-0218, immediate steps can be taken to secure affected systems and prevent unauthorized access.

Immediate Steps to Take

Utilize access lists or firewall filters to restrict CLI access to trusted networks. Limit access to the CLI for system administrators.

Long-Term Security Practices

Implement regular security audits, train staff on secure practices, and keep systems updated with the latest patches.

Patching and Updates

Juniper Networks has released updated software versions to mitigate the vulnerability. Ensure systems are updated to versions including 20.2R2.