CVE-2017-2346: An MS-MPC or MS-MIC Service PIC may crash when large fragmented packets are passed through an Application Layer Gateway (ALG). Repeated crashes of the...

Description

An MS-MPC or MS-MIC Service PIC may crash when large fragmented packets are passed through an Application Layer Gateway (ALG). Repeated crashes of the Service PC can result in an extended denial of service condition. The issue can be seen only if NAT or stateful-firewall rules are configured with ALGs enabled. This issue was caused by the code change for PR 1182910 in Junos OS 14.1X55-D30, 14.1X55-D35, 14.2R7, 15.1R5, and 16.1R2. No other versions of Junos OS and no other Juniper Networks products or platforms are affected by this issue. Affected releases are Juniper Networks Junos OS on MX platforms running: 14.1X55 from 14.1X55-D30 to releases prior to 14.1X55-D35; 14.2R from 14.2R7 to releases prior to 14.2R7-S4, 14.2R8; 15.1R from 15.1R5 to releases prior to 15.1R5-S2, 15.1R6; 16.1R from 16.1R2 to releases prior to 16.1R3-S2, 16.1R4.

Metrics

EPSS Probability

1.10%

61.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos	14.1x55	—
Juniper	Junos	14.2	R
Juniper	Junos	15.1	R
Juniper	Junos	16.1	R

References

http://www.securitytracker.com/id/1038895Third Party Advisory, VDB Entry
https://kb.juniper.net/JSA10794Vendor Advisory
http://www.securitytracker.com/id/1038895Third Party Advisory, VDB Entry
https://kb.juniper.net/JSA10794Vendor Advisory

Timeline

Published: Jul 17, 2017
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2017-2346?

An MS-MPC or MS-MIC Service PIC may crash when large fragmented packets are passed through an Application Layer Gateway (ALG). Repeated crashes of the Service PC can result in an extended denial of service condition. The issue can be seen only if NAT or stateful-firewall rules are configured with ALGs enabled. This issue was caused by the code change for PR 1182910 in Junos OS 14.1X55-D30, 14.1X55-D35, 14.2R7, 15.1R5, and 16.1R2. No other versions of Junos OS and no other Juniper Networks products or platforms are affected by this issue. Affected releases are Juniper Networks Junos OS on MX platforms running: 14.1X55 from 14.1X55-D30 to releases prior to 14.1X55-D35; 14.2R from 14.2R7 to releases prior to 14.2R7-S4, 14.2R8; 15.1R from 15.1R5 to releases prior to 15.1R5-S2, 15.1R6; 16.1R from 16.1R2 to releases prior to 16.1R3-S2, 16.1R4.

How severe is CVE-2017-2346?

Severity scoring for CVE-2017-2346 is pending analysis. The EPSS model estimates a 1.10% probability of exploitation in the next 30 days.

How do I fix CVE-2017-2346?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.