Vigil@nce: Linux kernel, privilege elevation via udp_sendmsg
August 2009 by Vigil@nce
A local attacker can use the MSG_MORE option on an UDP socket, in
order to force the kernel to dereference a NULL pointer.
Severity: 2/4
Consequences: administrator access/rights, denial of service of
computer
Provenance: user shell
Means of attack: no proof of concept, no attack
Ability of attacker: expert (4/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 24/08/2009
Revision date: 25/08/2009
IMPACTED PRODUCTS
– Debian Linux
– Linux kernel
– Novell Linux Desktop
– Novell Open Enterprise Server
– OpenSUSE
– Red Hat Enterprise Linux
– SUSE Linux Enterprise Server
DESCRIPTION OF THE VULNERABILITY
The MSG_MORE option of the sendmsg() function on a UDP socket
indicates that the next call to sendmsg() will contain data to be
added in the same packet.
However, when this option is used, the udp_sendmsg() and
udpv6_sendmsg() functions do not correctly handle the case where
the queue is empty, which forces the usage of a NULL pointer.
A local attacker can therefore use the MSG_MORE option on an UDP
socket, in order to force the kernel to stop.
A local attacker can also use this vulnerability with
VIGILANCE-VUL-8953 (https://vigilance.fr/tree/1/8953)/VIGILANCE-VUL-8861
(https://vigilance.fr/tree/1/8861) in order to elevate his
privileges.
CHARACTERISTICS
Identifiers: 518034, BID-36108, CVE-2009-2698, DSA 1872-1,
RHSA-2009:1222-02, RHSA-2009:1223-02, RHSA-2009:1233-01,
SUSE-SA:2009:046, VIGILANCE-VUL-8969
http://vigilance.fr/vulnerability/Linux-kernel-privilege-elevation-via-udp-sendmsg-8969