Amazon Linux AMI : kernel (ALAS-2011-16)

This script is Copyright (C) 2013-2014 Tenable Network Security, Inc.


Synopsis :

The remote Amazon Linux AMI host is missing a security update.

Description :

The skb_gro_header_slow function in include/linux/netdevice.h in the
Linux kernel before 2.6.39.4, when Generic Receive Offload (GRO) is
enabled, resets certain fields in incorrect situations, which allows
remote attackers to cause a denial of service (system crash) via
crafted network traffic.

Race condition in the ecryptfs_mount function in fs/ecryptfs/main.c in
the eCryptfs subsystem in the Linux kernel before 3.1 allows local
users to bypass intended file permissions via a mount.ecryptfs_private
mount with a mismatched uid.

The (1) IPv4 and (2) IPv6 implementations in the Linux kernel before
3.1 use a modified MD4 algorithm to generate sequence numbers and
Fragment Identification values, which makes it easier for remote
attackers to cause a denial of service (disrupted networking) or
hijack network sessions by predicting these values and sending crafted
packets.

Integer signedness error in the CIFSFindNext function in
fs/cifs/cifssmb.c in the Linux kernel before 3.1 allows remote CIFS
servers to cause a denial of service (memory corruption) or possibly
have unspecified other impact via a large length value in a response
to a read request for a directory.

The Performance Events subsystem in the Linux kernel before 3.1 does
not properly handle event overflows associated with
PERF_COUNT_SW_CPU_CLOCK events, which allows local users to cause a
denial of service (system hang) via a crafted application.

See also :

http://www.nessus.org/u?7175576a

Solution :

Run 'yum update kernel' to update your system. You will need to reboot
your system in order for the new kernel to be running.

Risk factor :

Critical / CVSS Base Score : 10.0
(CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C)

Family: Amazon Linux Local Security Checks

Nessus Plugin ID: 69575 ()

Bugtraq ID:

CVE ID: CVE-2011-1833
CVE-2011-2723
CVE-2011-2918
CVE-2011-3188
CVE-2011-3191