A vulnerability in the Network Address Translation - Protocol Translation (NAT-PT) feature of Junos OS on SRX series devices may allow a certain valid IPv6 packet to crash the flowd daemon. Repeated crashes of the flowd daemon can result in an extended denial of service condition for the SRX device.

Affected releases are Juniper Networks Junos OS:

• 12.1X46 versions prior to 12.1X46-D76;
• 12.3X48 versions prior to 12.3X48-D55;
• 15.1X49 versions prior to 15.1X49-D90.

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-2018-0017 .

The following software releases have been updated to resolve this specific issue: 12.1X46-D76 (pending release), 12.3X48-D55, 15.1X49-D90, 17.3R1, and all subsequent releases.

This issue is being tracked as  1261863  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/ .

There are no viable workarounds for this issue.

• 2018-04-11: Initial Publication.
• 2018-04-13: Updated problem section by fixing a typo in 12.1X46 affected versions. 12.1X46 versions prior to 12.1X46-D76 are affected, not 12.1X46-D72.

• 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