A vulnerability in Junos OS SNMP MIB-II subagent daemon (mib2d) may allow a remote network based attacker to cause the mib2d process to crash resulting in a denial of service condition (DoS) for the SNMP subsystem.

While a mib2d process crash can disrupt the network monitoring via SNMP, it does not impact routing, switching or firewall functionalities.

SNMP is disabled by default on devices running Junos OS.

Affected releases are Juniper Networks Junos OS:

• 12.1X46 versions prior to 12.1X46-D76;
• 12.3 versions prior to 12.3R12-S7, 12.3R13;
• 12.3X48 versions prior to 12.3X48-D65;
• 14.1 versions prior to 14.1R9;
• 14.1X53 versions prior to 14.1X53-D47 on QFX5100/EX4300/4600 & Legacy EX platforms;
• 14.1X53 versions prior to 14.1X53-D130 on QFabric;
• 15.1 versions prior to 15.1F2-S20, 15.1F6-S10, 15.1R7;
• 15.1X49 versions prior to 15.1X49-D130;
• 15.1X53 versions prior to 15.1X53-D58 on EX2300/EX3400;
• 15.1X53 versions prior to 15.1X53-D233 on QFX5200/QFX5110;
• 15.1X53 versions prior to 15.1X53-D471 on NFX;
• 15.1X53 versions prior to 15.1X53-D66 on QFX10;
• 16.1 versions prior to 16.1R5-S3, 16.1R7;
• 16.1X65 versions prior to 16.1X65-D47;
• 16.1X70 versions prior to 16.1X70-D10;
• 16.2 versions prior to 16.2R1-S6, 16.2R2-S5, 16.2R3;
• 17.1 versions prior to 17.1R2-S6, 17.1R3;

This issue only affects systems with SNMP mib2d enabled. SNMP is disabled by default on devices running Junos OS.

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

This issue was seen in a production network.

This issue has been assigned  CVE-2018-0019 .

The following software releases have been updated to resolve this specific issue:12.3R12-S7, 12.3R13, 12.3X48-D65, 14.1R9, 14.1X53-D130, 15.1F2-S20, 15.1F6-S10, 15.1R7, 15.1X49-D130, 15.1X53-D233, 15.1X53-D471, 15.1X53-D58, 15.1X53-D66, 16.1R5-S3, 16.1R7, 16.1X65-D65, 16.1X70-D10, 16.2R1-S6, 16.2R2-S5, 16.2R3, 17.1R2-S6, 17.1R3, 17.2R1, and all subsequent releases.

This issue is being tracked as  1241134  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/ .

Disable SNMP (disabled by default), utilize edge filtering with source-address validation (uRPF, etc.), access control lists (ACLs), and/or SNMPv3 authentication to limit access to the device only from trusted hosts.

• 2018-04-11: Initial Publication.
• 2018-04-25: Included 14.1X53 and 15.1X53 affected platforms.

• 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