An Improper Release of Memory Before Removing Last Reference vulnerability in the Session Initiation Protocol (SIP) Application Layer Gateway (ALG) of Juniper Networks Junos OS allows unauthenticated network-based attacker to cause a partial Denial of Service (DoS). On all MX and SRX platforms, if the SIP ALG is enabled, receipt of a specific SIP packet will create a stale SIP entry. Sustained receipt of such packets will cause the SIP call table to eventually fill up and cause a DoS for all SIP traffic. The SIP call usage can be monitored by "show security alg sip calls". To be affected the SIP ALG needs to be enabled, either implicitly / by default or by way of configuration. Please verify on SRX with: user@host> show security alg status | match sip SIP : Enabled Please verify on MX whether the following is configured: [ services ... rule <rule-name> (term <term-name>) from/match application/application-set <name> ] where either a. name = junos-sip or an application or application-s…