vulnerability in Juniper Networks Junos OS caused by Missing Release of Memory after Effective Lifetime leads to a memory leak each time the CLI command 'show system connections extensive' is executed. The amount of memory leaked on each execution depends on the number of TCP connections from and to the system. Repeated execution will cause more memory to leak and eventually daemons that need to allocate additionally memory and ultimately the kernel to crash, which will result in traffic loss.

Continued execution of this command will cause a sustained Denial of Service (DoS) condition.

An administrator can use the following CLI command to monitor for increase in memory consumption of the netstat process, if it exists:

The following log message might be observed if this issue happens:

This issue affects Juniper Networks Junos OS

• 18.2 versions prior to 18.2R2-S8, 18.2R3-S7.
• 18.3 versions prior to 18.3R3-S4;
• 18.4 versions prior to 18.4R1-S8, 18.4R2-S6, 18.4R3-S7;
• 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4;
• 19.2 versions prior to 19.2R1-S6, 19.2R3-S2;
• 19.3 versions prior to 19.3R2-S6, 19.3R3-S1;
• 19.4 versions prior to 19.4R1-S4, 19.4R2-S3, 19.4R3-S1;
• 20.1 versions prior to 20.1R2;
• 20.2 versions prior to 20.2R2-S1, 20.2R3;
• 20.3 versions prior to 20.3R1-S1, 20.3R2;

This issue does not affect Juniper Networks Junos OS versions prior to 18.2R1.

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-2021-0293 .
 

The following software releases have been updated to resolve this specific issue: Junos OS 18.2R2-S8, 18.2R3-S7, 18.3R3-S4, 18.4R1-S8, 18.4R2-S6, 18.4R3-S7, 19.1R1-S6, 19.1R2-S2, 19.1R3-S4, 19.2R1-S6, 19.2R3-S2, 19.3R2-S6, 19.3R3-S1, 19.3R3-S2, 19.4R1-S4, 19.4R2-S3, 19.4R3-S1, 20.1R2, 20.2R2-S1, 20.2R3, 20.3R1-S1, 20.3R2, 20.4R1, and all subsequent releases.

This issue is being tracked as  1548355 .
 

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

Please use ' show system connections ' (without extensive) and restrict access to 'show system connections extensive'.

To recover please use:

with the PID for the netstat process from the output of ' show system processes extensive '.
 

2021-07-14: Initial Publication.

• 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 Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2021-0293: Out-of-memory condition and crashes can occur after executing a certain CLI command repeatedly