If a duplicate MAC address is learned by two different interfaces on an MX Series device, the MAC address learning function correctly flaps between the interfaces. However, the Layer 2 Address Learning Daemon (L2ALD) daemon might crash when attempting to delete the duplicate MAC address when the particular entry is not found in the internal MAC address table.

This issue only occurs on MX Series devices with l2-backhaul VPN configured. No other products or platforms are affected by this issue.

Affected releases are Juniper Networks Junos OS:

• 15.1 versions prior to 15.1R7-S1 on MX Series;
• 16.1 versions prior to 16.1R4-S12, 16.1R6-S6 on MX Series;
• 16.2 versions prior to 16.2R2-S7 on MX Series;
• 17.1 versions prior to 17.1R2-S9 on MX Series;
• 17.2 versions prior to 17.2R1-S7, 17.2R2-S6 on MX Series;
• 17.3 versions prior to 17.3R2-S4, 17.3R3-S1 on MX Series;
• 17.4 versions prior to 17.4R1-S5 on MX Series;
• 18.1 versions prior to 18.1R2 on MX Series.

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-2018-0056 .
 

The following software releases have been updated to resolve this specific issue: 15.1R7-S1, 16.1R4-S12, 16.1R6-S6, 16.1R7, 16.2R2-S7, 16.2R3, 17.1R2-S9, 17.1R3, 17.2R1-S7, 17.2R2-S6, 17.2R3, 17.3R2-S4, 17.3R3-S1, 17.4R1-S5, 17.4R2, 18.1R2, 18.2R1, and all subsequent releases.

This fix has also been proactively committed into Junos OS: 15.1X49-D150, 15.1X53-D235, 15.1X53-D495, 15.1X53-D590, 15.1X53-D68, 18.2X75-D5, and all subsequent releases.

This issue is being tracked as PR  1338688  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/ .
 

​2018-10-10: 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 Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team
• CVE-2018-0056 at cve.mitre.org