CentOS: Security Advisory for ksh (CESA-2020:0568)

# Copyright (C) 2020 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.883187");
  script_version("2021-07-06T02:00:40+0000");
  script_cve_id("CVE-2019-14868");
  script_tag(name:"cvss_base", value:"7.2");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_tag(name:"last_modification", value:"2021-07-06 02:00:40 +0000 (Tue, 06 Jul 2021)");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-10-09 13:46:00 +0000 (Fri, 09 Oct 2020)");
  script_tag(name:"creation_date", value:"2020-02-27 04:00:26 +0000 (Thu, 27 Feb 2020)");
  script_name("CentOS: Security Advisory for ksh (CESA-2020:0568)");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2020 Greenbone Networks GmbH");
  script_family("CentOS Local Security Checks");
  script_dependencies("gather-package-list.nasl");
  script_mandatory_keys("ssh/login/centos", "ssh/login/rpms", re:"ssh/login/release=CentOS7");

  script_xref(name:"CESA", value:"2020:0568");
  script_xref(name:"URL", value:"https://lists.centos.org/pipermail/centos-announce/2020-February/035647.html");

  script_tag(name:"summary", value:"The remote host is missing an update for the 'ksh'
  package(s) announced via the CESA-2020:0568 advisory.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable package version is present on the target host.");

  script_tag(name:"insight", value:"KornShell (ksh) is a Unix shell developed by AT&T Bell Laboratories, which
is backward-compatible with the Bourne shell (sh) and includes many
features of the C shell. The most recent version is KSH-93. KornShell
complies with the POSIX.2 standard (IEEE Std 1003.2-1992).

Security Fix(es):

  * ksh: certain environment variables interpreted as arithmetic expressions
on startup, leading to code injection (CVE-2019-14868)

For more details about the security issue(s), including the impact, a CVSS
score, acknowledgments, and other related information, refer to the CVE
page(s) listed in the References section.");

  script_tag(name:"affected", value:"'ksh' package(s) on CentOS 7.");

  script_tag(name:"solution", value:"Please install the updated package(s).");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"package");

  exit(0);
}

include("revisions-lib.inc");
include("pkg-lib-rpm.inc");

release = rpm_get_ssh_release();
if(!release)
  exit(0);

res = "";
report = "";

if(release == "CentOS7") {

  if(!isnull(res = isrpmvuln(pkg:"ksh", rpm:"ksh~20120801~140.el7_7", rls:"CentOS7"))) {
    report += res;
  }

  if(report != "") {
    security_message(data:report);
  } else if(__pkg_match) {
    exit(99);
  }
  exit(0);
}

exit(0);