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Product Affected

This issue can affect all SRX Series services gateways.

Severity

High

Severity Assessment (CVSS) Score

7.5 (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Problem

Any SRX Series device with one or more ALGs enabled may experience a flowd crash when traffic is processed by the Sun/MS-RPC ALGs. This vulnerability in the Sun/MS-RPC ALG services component of Junos OS allows an attacker to cause a repeated denial of service against the target. Repeated traffic in a cluster may cause repeated flip-flop failure operations or full failure to the flowd daemon halting traffic on all nodes.

Only IPv6 traffic is affected by this issue. IPv4 traffic is unaffected. This issues is not seen with to-host traffic.

This issue has no relation with HA services themselves, only the ALG service.

Affected releases are Juniper Networks Junos OS 12.1X46 prior to 12.1X46-D55 on SRX; 12.1X47 prior to 12.1X47-D45 on SRX; 12.3X48 prior to 12.3X48-D32, 12.3X48-D35 on SRX; 15.1X49 prior to 15.1X49-D60 on SRX.

No other Juniper Networks products or platforms are affected by this issue.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability, however the issue has been seen in a production network.

This issue has been assigned CVE-2017-10608 .

Solution

The following software releases have been updated to resolve this specific issue: Junos OS 12.1X46-D55, 12.3X48-D32, 12.3X48-D35, 15.1X49-D60, 17.3R1 and all subsequent releases.

This issue is being tracked as PR 1189443 and is visible on the Customer Support website.

How to obtain fixed software:
Security vulnerabilities in Junos are fixed in the next available Maintenance Release of each supported Junos version. In some cases, a Maintenance Release is not planned to be available in an appropriate time-frame. For these cases, Service Releases are made available in order to be more timely. Security Advisory and Security Notices will indicate which Maintenance and Service Releases contain fixes for the issues described. Upon request to JTAC , customers will be provided download instructions for a Service Release. Although Juniper does not provide formal Release Note documentation for a Service Release, a list of "PRs fixed" can be provided on request.

Workaround

Disable Sun/MS-RPC ALGs on the SRX Series device.
Disable IPv6 on the device.
example:
deactivate interfaces xe-0/0/0 unit 0 family inet6 address 2000::254/64

Filtering incoming IPv6, or Sun/MS-RPC from the device is also an option.
example:
set interfaces xe-0/0/0 unit 0 family inet6 filter input TEST ==> apply to interface set firewall family inet6 filter TEST term t1 from destination-port 135 set firewall family inet6 filter TEST term t1 then discard

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History