2014-10 Security Bulletin: Junos: SRX flowd denial of service vulnerability related to ALGs (CVE-2014-3825)

Product Affected:This issue can affect all SRX Series services gateways.

Problem:On SRX Series devices, when any ALG (Application Layer Gateway) is enabled, a certain crafted packet may cause the flowd process to crash. Repeated crashes of the flowd process constitutes an extended denial of service condition for the SRX Series device. The status of ALGs can be obtained by executing the ‘show security alg status‘ CLI command.Juniper SIRT is not aware of any malicious exploitation of this vulnerability.No other Juniper Networks products or platforms are affected by this issue.This issue has been assigned CVE-2014-3825.

Solution:The following software releases have been updated to resolve this specific issue: Junos OS 11.4R12-S4, 12.1X44-D40, 12.1X45-D30, 12.1X46-D25, 12.1X47-D10, and all subsequent releases.This issue is being tracked as PR 986369 and is visible on the Customer Support website.KB16765 – “In which releases are vulnerabilities fixed?” describes which release vulnerabilities are fixed as per our End of Engineering and End of Life support policies.

Workaround:Two available workarounds exist for this issue:Disable ALGs using the CLI command ‘set security alg ____ disable‘ if ALGs are not requiredEnable flow-based processing for IPv6 traffic using the CLI command ‘set security forwarding-options family inet6 mode flow-based‘ command (a device reboot is required)

Implementation: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.

Related Links: CVSS Score:7.8 (AV:N/AC:L/Au:N/C:N/I:N/A:C)

Risk Level:High

Risk Assessment:Information for how Juniper Networks uses CVSS can be found at KB 16446 “Common Vulnerability Scoring System (CVSS) and Juniper’s Security Advisories.”

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