A report has been received from Juniper at 4:25pm under bulletin PSN-2010-01-623 that a crafted malformed TCP field option in the TCP header of a packet will cause the JUNOS kernel to core (crash). In other words the kernel on the network device (gateway router) will crash and reboot if a packet containing this crafted option is received on a listening TCP port. The JUNOS firewall filter is unable to filter a TCP packet with this issue. Juniper claims this issue as exploit was identified during investigation of a vendor interoperability issue.
There is talk that backbone Internet providers have been quickly patching this issue since yesterday night.
For more information, please read this blog: