Debian DLA-1723-1 : cron security update

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Debian Security Advisory DLA-1723-1. The text
# itself is copyright (C) Software in the Public Interest, Inc.
#

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

if (description)
{
  script_id(123017);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/06/13");

  script_cve_id(
    "CVE-2017-9525",
    "CVE-2019-9704",
    "CVE-2019-9705",
    "CVE-2019-9706"
  );

  script_name(english:"Debian DLA-1723-1 : cron security update");

  script_set_attribute(attribute:"synopsis", value:
"The remote Debian host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"Various security problems have been discovered in Debian's CRON
scheduler.

CVE-2017-9525

Fix group crontab to root escalation via the Debian package's postinst
script as described by Alexander Peslyak (Solar Designer) in
http://www.openwall.com/lists/oss-security/2017/06/08/3

CVE-2019-9704

DoS: Fix unchecked return of calloc(). Florian Weimer discovered that
a missing check for the return value of calloc() could crash the
daemon, which could be triggered by a very large crontab created by a
user.

CVE-2019-9705

Enforce maximum crontab line count of 1000 to prevent a malicious user
from creating an excessivly large crontab. The daemon will log a
warning for existing files, and crontab(1) will refuse to create new
ones.

CVE-2019-9706

A user reported a use-after-free condition in the cron daemon, leading
to a possible denial of service scenario by crashing the daemon. 

For Debian 8 'Jessie', these problems have been fixed in version
3.0pl1-127+deb8u2.

We recommend that you upgrade your cron packages.

NOTE: Tenable Network Security has extracted the preceding description
block directly from the DLA security advisory. Tenable has attempted
to automatically clean and format it as much as possible without
introducing additional issues.");
  script_set_attribute(attribute:"see_also", value:"https://www.openwall.com/lists/oss-security/2017/06/08/3");
  script_set_attribute(attribute:"see_also", value:"https://lists.debian.org/debian-lts-announce/2019/03/msg00025.html");
  script_set_attribute(attribute:"see_also", value:"https://packages.debian.org/source/jessie/cron");
  script_set_attribute(attribute:"solution", value:
"Upgrade the affected cron package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-9525");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/06/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/03/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/03/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:cron");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:8.0");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2019-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("debian_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (deb_check(release:"8.0", prefix:"cron", reference:"3.0pl1-127+deb8u2")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:deb_report_get());
  else security_warning(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");