A denial of service vulnerability in the telnetd service on Junos OS allows remote unauthenticated users to cause high CPU usage which may affect system performance.

Affected releases are Juniper Networks Junos OS:

• 12.1X46 versions prior to 12.1X46-D81 on SRX Series;
• 12.3 versions prior to 12.3R12-S11;
• 12.3X48 versions prior to 12.3X48-D80 on SRX Series;
• 15.1 versions prior to 15.1R7;
• 15.1X49 versions prior to 15.1X49-D150, 15.1X49-D160 on SRX Series;
• 15.1X53 versions prior to 15.1X53-D59 on EX2300/EX3400 Series;
• 15.1X53 versions prior to 15.1X53-D68 on QFX10K Series;
• 15.1X53 versions prior to 15.1X53-D235 on QFX5200/QFX5110 Series;
• 15.1X53 versions prior to 15.1X53-D495 on NFX Series;
• 16.1 versions prior to 16.1R4-S12, 16.1R6-S6, 16.1R7;
• 16.2 versions prior to 16.2R2-S7, 16.2R3;
• 17.1 versions prior to 17.1R2-S9, 17.1R3;
• 17.2 versions prior to 17.2R2-S6, 17.2R3;
• 17.2X75 versions prior to 17.2X75-D100;
• 17.3 versions prior to 17.3R2-S4, 17.3R3;
• 17.4 versions prior to 17.4R1-S5, 17.4R2;
• 18.2X75 versions prior to 18.2X75-D5.

This issue affects devices with telnet service enabled.

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

This issue was found during internal product security testing or research.

This issue has been assigned  CVE-2018-0061 .
 

The following software releases have been updated to resolve this specific issue: 12.1X46-D81, 12.3R12-S11, 12.3R13, 12.3X48-D80, 15.1R7, 15.1X49-D150, 15.1X49-D160, 15.1X53-D235, 15.1X53-D495, 15.1X53-D59, 15.1X53-D68, 16.1R4-S12, 16.1R6-S6, 16.1R7, 16.2R2-S7, 16.2R3, 17.1R2-S9, 17.1R3, 17.2R2-S6, 17.2R3, 17.2X75-D100, 17.2X75-D110, 17.3R2-S4, 17.3R3, 17.4R1-S5, 17.4R2, 18.1R1, 18.1R2, 18.2R1, 18.2X75-D5, and all subsequent releases.

This issue is being tracked as PR  1331234  which is visible on the Customer Support website.

Note: Juniper SIRT's  policy  is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).
 

Software Releases, patches and updates are available at  https://www.juniper.net/support/downloads/ .
 

Disabling the telnet service will completely mitigate this issue.
 

​2018-10-10: Initial publication

• KB16613: Overview of the Juniper Networks SIRT Monthly 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