fs/namespace.c in the Linux kernel through 3.16.1 does not properly restrict clearing MNT_NODEV, MNT_NOSUID, and MNT_NOEXEC and changing MNT_ATIME_MASK during a remount of a bind mount, which allows local users to gain privileges, interfere with backups and auditing on systems that had atime enabled, or cause a denial of service (excessive filesystem updating) on systems that had atime disabled via a ‘mount -o remount’ command within a user namespace.
The do_remount function in fs/namespace.c in the Linux kernel through 3.16.1 does not maintain the MNT_LOCK_READONLY bit across a remount of a bind mount, which allows local users to bypass an intended read-only restriction and defeat certain sandbox protection mechanisms via a ‘mount -o remount’ command within a user namespace.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2014-417.
#
include("compat.inc");
if (description)
{
script_id(78360);
script_version("1.3");
script_cvs_date("Date: 2018/04/18 15:09:35");
script_cve_id("CVE-2014-5206", "CVE-2014-5207");
script_xref(name:"ALAS", value:"2014-417");
script_name(english:"Amazon Linux AMI : kernel (ALAS-2014-417)");
script_summary(english:"Checks rpm output for the updated packages");
script_set_attribute(
attribute:"synopsis",
value:"The remote Amazon Linux AMI host is missing a security update."
);
script_set_attribute(
attribute:"description",
value:
"fs/namespace.c in the Linux kernel through 3.16.1 does not properly
restrict clearing MNT_NODEV, MNT_NOSUID, and MNT_NOEXEC and changing
MNT_ATIME_MASK during a remount of a bind mount, which allows local
users to gain privileges, interfere with backups and auditing on
systems that had atime enabled, or cause a denial of service
(excessive filesystem updating) on systems that had atime disabled via
a 'mount -o remount' command within a user namespace.
The do_remount function in fs/namespace.c in the Linux kernel through
3.16.1 does not maintain the MNT_LOCK_READONLY bit across a remount of
a bind mount, which allows local users to bypass an intended read-only
restriction and defeat certain sandbox protection mechanisms via a
'mount -o remount' command within a user namespace."
);
script_set_attribute(
attribute:"see_also",
value:"https://alas.aws.amazon.com/ALAS-2014-417.html"
);
script_set_attribute(
attribute:"solution",
value:
"Run 'yum update kernel' to update your system. You will need to reboot
your system in order for the new kernel to be running."
);
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-doc");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-headers");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-debuginfo");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:kernel-tools-devel");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:perf-debuginfo");
script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");
script_set_attribute(attribute:"patch_publication_date", value:"2014/09/18");
script_set_attribute(attribute:"plugin_publication_date", value:"2014/10/12");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2014-2018 Tenable Network Security, Inc.");
script_family(english:"Amazon Linux Local Security Checks");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");
exit(0);
}
include("audit.inc");
include("global_settings.inc");
include("rpm.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "A")
{
if (os_ver == 'A') os_ver = 'AMI';
audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}
if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);
flag = 0;
if (rpm_check(release:"ALA", reference:"kernel-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-debuginfo-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"i686", reference:"kernel-debuginfo-common-i686-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"x86_64", reference:"kernel-debuginfo-common-x86_64-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-devel-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-doc-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-headers-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-debuginfo-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-devel-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-3.14.19-17.43.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-debuginfo-3.14.19-17.43.amzn1")) flag++;
if (flag)
{
if (report_verbosity > 0) security_hole(port:0, extra:rpm_report_get());
else security_hole(0);
exit(0);
}
else
{
tested = pkg_tests_get();
if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
else audit(AUDIT_PACKAGE_NOT_INSTALLED, "kernel / kernel-debuginfo / kernel-debuginfo-common-i686 / etc");
}
Vendor | Product | Version | CPE |
---|---|---|---|
amazon | linux | kernel | p-cpe:/a:amazon:linux:kernel |
amazon | linux | kernel-debuginfo | p-cpe:/a:amazon:linux:kernel-debuginfo |
amazon | linux | kernel-debuginfo-common-i686 | p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686 |
amazon | linux | kernel-debuginfo-common-x86_64 | p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64 |
amazon | linux | kernel-devel | p-cpe:/a:amazon:linux:kernel-devel |
amazon | linux | kernel-doc | p-cpe:/a:amazon:linux:kernel-doc |
amazon | linux | kernel-headers | p-cpe:/a:amazon:linux:kernel-headers |
amazon | linux | kernel-tools | p-cpe:/a:amazon:linux:kernel-tools |
amazon | linux | kernel-tools-debuginfo | p-cpe:/a:amazon:linux:kernel-tools-debuginfo |
amazon | linux | kernel-tools-devel | p-cpe:/a:amazon:linux:kernel-tools-devel |