NewStart CGSL CORE 5.04 / MAIN 5.04 : kernel-rt Multiple Vulnerabilities (NS-SA-2019-0162)

2019-08-1200:00:00

www.tenable.com

The remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has kernel-rt packages installed that are affected by multiple vulnerabilities:

An integer overflow flaw was found in the way the Linux kernel’s networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel’s socket buffer (SKB) data structure becomes fragmented. Each fragment is about TCP maximum segment size (MSS) bytes. To efficiently process SACK blocks, the Linux kernel merges multiple fragmented SKBs into one, potentially overflowing the variable holding the number of segments. A remote attacker could use this flaw to crash the Linux kernel by sending a crafted sequence of SACK segments on a TCP connection with small value of TCP MSS, resulting in a denial of service (DoS). (CVE-2019-11477)
An excessive resource consumption flaw was found in the way the Linux kernel’s networking subsystem processed TCP Selective Acknowledgment (SACK) segments. While processing SACK segments, the Linux kernel’s socket buffer (SKB) data structure becomes fragmented, which leads to increased resource utilization to traverse and process these fragments as further SACK segments are received on the same TCP connection. A remote attacker could use this flaw to cause a denial of service (DoS) by sending a crafted sequence of SACK segments on a TCP connection. (CVE-2019-11478)
An excessive resource consumption flaw was found in the way the Linux kernel’s networking subsystem processed TCP segments. If the Maximum Segment Size (MSS) of a TCP connection was set to low values, such as 48 bytes, it can leave as little as 8 bytes for the user data, which significantly increases the Linux kernel’s resource (CPU, Memory, and Bandwidth) utilization. A remote attacker could use this flaw to cause a denial of service (DoS) by repeatedly sending network traffic on a TCP connection with low TCP MSS. (CVE-2019-11479)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2019-0162. The text
# itself is copyright (C) ZTE, Inc.

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(127444);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/12/06");

  script_cve_id("CVE-2019-11477", "CVE-2019-11478", "CVE-2019-11479");
  script_xref(name:"CEA-ID", value:"CEA-2019-0456");

  script_name(english:"NewStart CGSL CORE 5.04 / MAIN 5.04 : kernel-rt Multiple Vulnerabilities (NS-SA-2019-0162)");

  script_set_attribute(attribute:"synopsis", value:
"The remote machine is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has kernel-rt packages installed that are affected
by multiple vulnerabilities:

  - An integer overflow flaw was found in the way the Linux
    kernel's networking subsystem processed TCP Selective
    Acknowledgment (SACK) segments. While processing SACK
    segments, the Linux kernel's socket buffer (SKB) data
    structure becomes fragmented. Each fragment is about TCP
    maximum segment size (MSS) bytes. To efficiently process
    SACK blocks, the Linux kernel merges multiple fragmented
    SKBs into one, potentially overflowing the variable
    holding the number of segments. A remote attacker could
    use this flaw to crash the Linux kernel by sending a
    crafted sequence of SACK segments on a TCP connection
    with small value of TCP MSS, resulting in a denial of
    service (DoS). (CVE-2019-11477)

  - An excessive resource consumption flaw was found in the
    way the Linux kernel's networking subsystem processed
    TCP Selective Acknowledgment (SACK) segments. While
    processing SACK segments, the Linux kernel's socket
    buffer (SKB) data structure becomes fragmented, which
    leads to increased resource utilization to traverse and
    process these fragments as further SACK segments are
    received on the same TCP connection. A remote attacker
    could use this flaw to cause a denial of service (DoS)
    by sending a crafted sequence of SACK segments on a TCP
    connection. (CVE-2019-11478)

  - An excessive resource consumption flaw was found in the
    way the Linux kernel's networking subsystem processed
    TCP segments. If the Maximum Segment Size (MSS) of a TCP
    connection was set to low values, such as 48 bytes, it
    can leave as little as 8 bytes for the user data, which
    significantly increases the Linux kernel's resource
    (CPU, Memory, and Bandwidth) utilization. A remote
    attacker could use this flaw to cause a denial of
    service (DoS) by repeatedly sending network traffic on a
    TCP connection with low TCP MSS. (CVE-2019-11479)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/notice/NS-SA-2019-0162");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL kernel-rt packages. Note that updated packages may not be available yet. Please contact ZTE
for more information.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-11477");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/06/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/08/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"NewStart CGSL Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2019-2022 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/ZTE-CGSL/release", "Host/ZTE-CGSL/rpm-list", "Host/cpu");

  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/ZTE-CGSL/release");
if (isnull(release) || release !~ "^CGSL (MAIN|CORE)") audit(AUDIT_OS_NOT, "NewStart Carrier Grade Server Linux");

if (release !~ "CGSL CORE 5.04" &&
    release !~ "CGSL MAIN 5.04")
  audit(AUDIT_OS_NOT, 'NewStart CGSL CORE 5.04 / NewStart CGSL MAIN 5.04');

if (!get_kb_item("Host/ZTE-CGSL/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "NewStart Carrier Grade Server Linux", cpu);

flag = 0;

pkgs = {
  "CGSL CORE 5.04": [
    "kernel-rt-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-devel-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-kvm-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-kvm-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debuginfo-common-x86_64-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-devel-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-doc-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-kvm-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-kvm-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-devel-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-kvm-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-kvm-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f"
  ],
  "CGSL MAIN 5.04": [
    "kernel-rt-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-devel-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-kvm-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debug-kvm-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-debuginfo-common-x86_64-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-devel-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-doc-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-kvm-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-kvm-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-devel-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-kvm-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f",
    "kernel-rt-trace-kvm-debuginfo-3.10.0-693.21.1.rt56.639.el7.cgslv5_4.16.255.g83b1c3f"
  ]
};
pkg_list = pkgs[release];

foreach (pkg in pkg_list)
  if (rpm_check(release:"ZTE " + release, reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "kernel-rt");
}