An Improper Initialization vulnerability in Juniper Networks Junos OS Evolved may cause a commit operation for disabling the telnet service to not take effect as expected, resulting in the telnet service staying enabled.

When it is not intended to be operating on the device, an administrator can issue the following command to verify whether telnet is operating in the background:

This issue affects Juniper Networks Junos OS Evolved:

• All versions prior to 20.4R2-S2-EVO, 20.4R3-EVO;
• 21.1 version 21.1R1-EVO and later versions;
• 21.2 versions prior to 21.2R2-EVO;
• 21.4 versions prior to 21.4R3-S3-EVO;
• 22.2 versions prior to 22.2R3-EVO;
• 22.3 versions prior to 22.3R2-EVO;
• 22.4 versions prior to 22.4R2-EVO.

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

This issue was seen during production usage.

This issue has been assigned CVE-2022-22164 .

The following software releases have been updated to resolve this specific issue: Junos OS Evolved: 20.4R2-S2-EVO, 20.4R3-EVO, 21.2R2-EVO, 21.4R3-S3-EVO, 22.2R3-EVO, 22.3R2-EVO, 22.4R2-EVO, 23.2R1-EVO, and all subsequent releases.
 

This issue is being tracked as 1596411.and 1690827  

Software releases or updates are available for download at https://support.juniper.net/support/downloads/

To work around the issue, the xinetd service can be restarted manually using one of the commands below:

or

Additionally, loopback/firewall filters can be applied to disable remote access to the telnet service.

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2022-22164: Telnet service may be enabled when it is expected to be disabled