Junos OS: SRX Series: Crafted HTTP traffic may cause UTM to consume all mbufs, leading to Denial of Service

An SRX Series Service Gateway configured for Unified Threat Management (UTM) may experience a system crash with the error message "mbuf exceed" -- an indication of memory buffer exhaustion -- due to the receipt of crafted HTTP traffic. Each crafted HTTP packet inspected by UTM consumes mbufs which can be identified through the following log messages: all_logs.0:Jun 8 03:25:03 srx1 node0.fpc4 : SPU3 jmpi mbuf stall 50%. all_logs.0:Jun 8 03:25:13 srx1 node0.fpc4 : SPU3 jmpi mbuf stall 51%. all_logs.0:Jun 8 03:25:24 srx1 node0.fpc4 : SPU3 jmpi mbuf stall 52%. ... Eventually the system runs out of mbufs and the system crashes (fails over) with the error "mbuf exceed". This issue only occurs when HTTP AV inspection is configured. Devices configured for Web Filtering alone are unaffected by this issue. Affected releases are Junos OS on SRX Series: 12.1X46 versions prior to 12.1X46-D81; 12.3X48 versions prior to 12.3X48-D77; 15.1X49 versions prior to 15.1X49-D101, 15.1X49-D110.