CVE-2017-2346

MS-MPC or MS-MIC crash when passing large fragmented traffic through an ALG

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.

Remediation

Workaround:

There are no viable workarounds for this issue. If NAT and stateful-firewall are not required, disabling them in the [edit applications] stanza will mitigate this issue. It is good security practice to limit the exploitable attack surface of critical infrastructure networking equipment. Use access lists or firewall filters to limit access to the device from trusted, administrative networks or hosts.

5.9

CVSS

Severity: Medium

CVSS 3.0 •

CVSS 2.0 •

EPSS 0.27%

Vendor Advisory juniper.net

Affected: Juniper Networks Junos OS

References

Link	Tags
http://www.securitytracker.com/id/1038895	third party advisory vdb entry
https://kb.juniper.net/JSA10794	vendor advisory

Frequently Asked Questions

What is the severity of CVE-2017-2346?: CVE-2017-2346 has been scored as a medium severity vulnerability.
How to fix CVE-2017-2346?: As a workaround for remediating CVE-2017-2346: There are no viable workarounds for this issue. If NAT and stateful-firewall are not required, disabling them in the [edit applications] stanza will mitigate this issue. It is good security practice to limit the exploitable attack surface of critical infrastructure networking equipment. Use access lists or firewall filters to limit access to the device from trusted, administrative networks or hosts.
Is CVE-2017-2346 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2017-2346 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2017-2346?: CVE-2017-2346 affects Juniper Networks Junos OS.