Solaris 10 systems may panic in the tcp_fuse_rcv_drain() TCP/IP function when using TCP loopback connections, where both ends of the connection are on the same system. This may allow a local unprivileged user to cause a Denial of Service (DoS) condition on the affected host.

This issue can occur in the following releases:

SPARC Platform

• Solaris 10 without patch 118833-23

x86 Platform

• Solaris 10 without patch 118855-19

Note: Solaris 8 and Solaris 9 are not impacted by this issue.

A system panic in tcp_fuse_rcv_drain() TCP/IP function is representative of this issue.

To work around the described issue until patches can be installed, disable TCP Fusion by adding the following line to the "/etc/system" file and rebooting the system:

    set ip:do_tcp_fusion = 0x0

Undo the above change to the "/etc/system" file and reboot to re-enable TCP Fusion.

Note: The workaround option above may affect performance.

This issue is addressed in the following releases:

SPARC Platform

• Solaris 10 with patch 118833-23 or later

x86 Platform

• Solaris 10 with patch 118855-19 or later

This solution has no attachment