Paul Starzetz has reported some vulnerabilities in the Linux Kernel, which can be exploited by malicious people to cause a DoS (Denial of Service), and by malicious, local users to cause a DoS, gain knowledge of sensitive information, or potentially gain escalated privileges.

1) An error in the "ip_mc_source()" function of the IGMP (Internet Group Management Protocol) subsystem can be exploited by malicious, local users to overwrite kernel memory, which crashes the system and may allow users to gain escalated privileges.

This vulnerability can also be further exploited via the "ip_mc_msfget()" and "ip_mc_gsfget()" user API functions to disclose large portions of kernel memory.

2) The "igmp_marksources()" function of the IGMP networking module does not validate received IGMP message parameters properly, which may result in an out-of-bounds memory access error. This can be exploited by malicious people to cause a vulnerable system to hang or potentially crash via specially crafted IGMP_HOST_MEMBERSHIP_QUERY messages.

Successful exploitation requires that the kernel is compiled with multicasting support and is processing incoming IGMP packets. It is further required that an application has a bound multicast socket with attached source filter.

3) A deadlock condition in the "__scm_send()" scm message parsing function can be exploited by malicious, local users to cause the system to hang via a specially crafted auxiliary message sent to a socket.

The vulnerabilities have been reported in versions 2.4 through 2.4.28 and 2.6 through 2.6.9.

Solution
Update to version 2.4.29 or later, or 2.6.10 or later.

Provided and/or discovered by
Paul Starzetz

Changelog
Further details available to Secunia VIM customers

Original Advisory
http://isec.pl/vulnerabilities/isec-0018-igmp.txt
http://isec.pl/vulnerabilities/isec-0019-scm.txt

Deep Links
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