A flaw was found in the Linux kernel’s NFS41+ subsystem. NFS41+ shares mounted in different network namespaces at the same time can make bc_svc_process() use wrong back-channel IDs and cause a use-after-free vulnerability. Thus a malicious container user can cause a host kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out. (CVE-2018-16884)
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2019-1149.
#
include("compat.inc");
if (description)
{
script_id(121370);
script_version("1.3");
script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/20");
script_cve_id("CVE-2018-16884");
script_xref(name:"ALAS", value:"2019-1149");
script_name(english:"Amazon Linux AMI : kernel (ALAS-2019-1149)");
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:
"A flaw was found in the Linux kernel's NFS41+ subsystem. NFS41+ shares
mounted in different network namespaces at the same time can make
bc_svc_process() use wrong back-channel IDs and cause a use-after-free
vulnerability. Thus a malicious container user can cause a host kernel
memory corruption and a system panic. Due to the nature of the flaw,
privilege escalation cannot be fully ruled out. (CVE-2018-16884)"
);
script_set_attribute(
attribute:"see_also",
value:"https://alas.aws.amazon.com/ALAS-2019-1149.html"
);
script_set_attribute(
attribute:"solution",
value:"Run 'yum update kernel' to update your system."
);
script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:S/C:P/I:P/A:C");
script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
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-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:"vuln_publication_date", value:"2018/12/18");
script_set_attribute(attribute:"patch_publication_date", value:"2019/01/25");
script_set_attribute(attribute:"plugin_publication_date", value:"2019/01/25");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
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-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-debuginfo-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"i686", reference:"kernel-debuginfo-common-i686-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", cpu:"x86_64", reference:"kernel-debuginfo-common-x86_64-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-devel-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-headers-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-debuginfo-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"kernel-tools-devel-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-4.14.94-73.73.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"perf-debuginfo-4.14.94-73.73.amzn1")) flag++;
if (flag)
{
if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
else security_warning(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-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 |
amazon | linux | perf | p-cpe:/a:amazon:linux:perf |