Vulnerabilities > CVE-2008-1845 - Local Privilege Escalation vulnerability in Mirbsd Miros 33

047910
CVSS 7.2 - HIGH
Attack vector
LOCAL
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
local
low complexity
mirbsd
nessus

Summary

The Korn shell (aka mksh) before R33d on MirOS (aka MirBSD) does not flush the tty's I/O when invoking mksh in a new terminal, which allows local users to gain privileges by opening a virtual terminal and entering command sequences, which might later be executed in opportunistic circumstances by a different user who launches mksh and specifies that terminal with the -T option.

Vulnerable Configurations

Part Description Count
OS
Mirbsd
3

Nessus

NASL familyFreeBSD Local Security Checks
NASL idFREEBSD_PKG_86C0555012C111DDBAB70016179B2DD5.NASL
descriptionSecunia reports : The vulnerability is caused due to an error when attaching to a TTY via the -T command line switch. This can be exploited to execute arbitrary commands with the privileges of the user running mksh via characters previously written to the attached virtual console.
last seen2020-06-01
modified2020-06-02
plugin id32067
published2008-04-28
reporterThis script is Copyright (C) 2008-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/32067
titleFreeBSD : mksh -- TTY attachment privilege escalation (86c05550-12c1-11dd-bab7-0016179b2dd5)
code
#%NASL_MIN_LEVEL 80502
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2018 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
#    copyright notice, this list of conditions and the following
#    disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
#    published online in any format, converted to PDF, PostScript,
#    RTF and other formats) must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer
#    in the documentation and/or other materials provided with the
#    distribution.
# 
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#

include("compat.inc");

if (description)
{
  script_id(32067);
  script_version("1.12");
  script_cvs_date("Date: 2019/08/02 13:32:39");

  script_cve_id("CVE-2008-1845");
  script_xref(name:"Secunia", value:"29803");

  script_name(english:"FreeBSD : mksh -- TTY attachment privilege escalation (86c05550-12c1-11dd-bab7-0016179b2dd5)");
  script_summary(english:"Checks for updated package in pkg_info output");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote FreeBSD host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Secunia reports :

The vulnerability is caused due to an error when attaching to a TTY
via the -T command line switch. This can be exploited to execute
arbitrary commands with the privileges of the user running mksh via
characters previously written to the attached virtual console."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.mirbsd.org/mksh.htm#clog"
  );
  # https://vuxml.freebsd.org/freebsd/86c05550-12c1-11dd-bab7-0016179b2dd5.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?411e2727"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:mksh");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2008/04/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2008/04/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2008/04/28");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2008-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"FreeBSD Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  exit(0);
}


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


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"mksh<R33d")) flag++;

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