Amazon Linux AMI : telnet (ALAS-2020-1387)

2020-07-02T00:00:00
ID ALA_ALAS-2020-1387.NASL
Type nessus
Reporter This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
Modified 2020-07-02T00:00:00

Description

utility.c in telnetd in netkit telnet through 0.17 allows remote attackers to execute arbitrary code via short writes or urgent data, because of a buffer overflow involving the netclear and nextitem functions. (CVE-2020-10188)

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2020-1387.
#

include("compat.inc");

if (description)
{
  script_id(138058);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/07/10");

  script_cve_id("CVE-2020-10188");
  script_xref(name:"ALAS", value:"2020-1387");
  script_xref(name:"IAVA", value:"2020-A-0293");

  script_name(english:"Amazon Linux AMI : telnet (ALAS-2020-1387)");
  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:
"utility.c in telnetd in netkit telnet through 0.17 allows remote
attackers to execute arbitrary code via short writes or urgent data,
because of a buffer overflow involving the netclear and nextitem
functions. (CVE-2020-10188)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2020-1387.html"
  );
  script_set_attribute(
    attribute:"solution",
    value:"Run 'yum update telnet' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/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: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:telnet");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:telnet-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:telnet-server");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/03/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/06/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/07/02");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 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:"telnet-0.17-49.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"telnet-debuginfo-0.17-49.9.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"telnet-server-0.17-49.9.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, "telnet / telnet-debuginfo / telnet-server");
}