A certain crafted HTTP packet can trigger an uninitialized function pointer deference vulnerability in the Packet Forwarding Engine manager (fxpc) on all EX, QFX and MX Series devices in a Virtual Chassis configuration. This issue can result in a crash of the fxpc daemon or may potentially lead to remote code execution. This issue only occurs when the crafted packet it destined to the device. Affected releases are Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D47 on EX and QFX Virtual Chassis Platforms; 15.1 versions prior to 15.1R7-S3 all Virtual Chassis Platforms 15.1X53 versions prior to 15.1X53-D50 on EX and QFX Virtual Chassis Platforms.