Vulnerabilities > CVE-2020-3143 - Path Traversal vulnerability in Cisco products

047910
CVSS 7.2 - HIGH
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
HIGH
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
cisco
CWE-22
nessus

Summary

A vulnerability in the video endpoint API (xAPI) of Cisco TelePresence Collaboration Endpoint (CE) Software, Cisco TelePresence Codec (TC) Software, and Cisco RoomOS Software could allow an authenticated, remote attacker to conduct directory traversal attacks on an affected device. The vulnerability is due to insufficient validation of user-supplied input to the xAPI of the affected software. An attacker could exploit this vulnerability by sending a crafted request to the xAPI. A successful exploit could allow the attacker to read and write arbitrary files in the system. To exploit this vulnerability, an attacker would need either an In-Room Control or administrator account.

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Relative Path Traversal
    An attacker exploits a weakness in input validation on the target by supplying a specially constructed path utilizing dot and slash characters for the purpose of obtaining access to arbitrary files or resources. An attacker modifies a known path on the target in order to reach material that is not available through intended channels. These attacks normally involve adding additional path separators (/ or \) and/or dots (.), or encodings thereof, in various combinations in order to reach parent directories or entirely separate trees of the target's directory structure.
  • Directory Traversal
    An attacker with access to file system resources, either directly or via application logic, will use various file path specification or navigation mechanisms such as ".." in path strings and absolute paths to extend their range of access to inappropriate areas of the file system. The attacker attempts to either explore the file system for recon purposes or access directories and files that are intended to be restricted from their access. Exploring the file system can be achieved through constructing paths presented to directory listing programs, such as "ls" and 'dir', or through specially crafted programs that attempt to explore the file system. The attacker engaging in this type of activity is searching for information that can be used later in a more exploitive attack. Access to restricted directories or files can be achieved through modification of path references utilized by system applications.
  • File System Function Injection, Content Based
    An attack of this type exploits the host's trust in executing remote content including binary files. The files are poisoned with a malicious payload (targeting the file systems accessible by the target software) by the attacker and may be passed through standard channels such as via email, and standard web content like PDF and multimedia files. The attacker exploits known vulnerabilities or handling routines in the target processes. Vulnerabilities of this type have been found in a wide variety of commercial applications from Microsoft Office to Adobe Acrobat and Apple Safari web browser. When the attacker knows the standard handling routines and can identify vulnerabilities and entry points they can be exploited by otherwise seemingly normal content. Once the attack is executed, the attackers' program can access relative directories such as C:\Program Files or other standard system directories to launch further attacks. In a worst case scenario, these programs are combined with other propagation logic and work as a virus.
  • Using Slashes and URL Encoding Combined to Bypass Validation Logic
    This attack targets the encoding of the URL combined with the encoding of the slash characters. An attacker can take advantage of the multiple way of encoding an URL and abuse the interpretation of the URL. An URL may contain special character that need special syntax handling in order to be interpreted. Special characters are represented using a percentage character followed by two digits representing the octet code of the original character (%HEX-CODE). For instance US-ASCII space character would be represented with %20. This is often referred as escaped ending or percent-encoding. Since the server decodes the URL from the requests, it may restrict the access to some URL paths by validating and filtering out the URL requests it received. An attacker will try to craft an URL with a sequence of special characters which once interpreted by the server will be equivalent to a forbidden URL. It can be difficult to protect against this attack since the URL can contain other format of encoding such as UTF-8 encoding, Unicode-encoding, etc.
  • Manipulating Input to File System Calls
    An attacker manipulates inputs to the target software which the target software passes to file system calls in the OS. The goal is to gain access to, and perhaps modify, areas of the file system that the target software did not intend to be accessible.

Nessus

NASL familyCISCO
NASL idCISCO-SA-TELEPRESENCE-PATH-TR-WDRNYEZZ.NASL
descriptionAccording to its self-reported version, the Cisco TelePresence Codec (TC) and Collaboration Endpoint (CE) Cisco TelePresence Software is affected by a directory traversal vulnerability. An authenticated, remote attacker can exploit this vulnerability in order to read and write arbitrary files on the remote host. Please see the included Cisco BIDs and Cisco Security Advisory for more information
last seen2020-03-17
modified2020-02-07
plugin id133530
published2020-02-07
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/133530
titleCisco TelePresence Endpoint Software Path Traversal (cisco-sa-telepresence-path-tr-wdrnYEZZ)
code
#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(133530);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/07");

  script_cve_id("CVE-2020-3143");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvs45241");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvs67675");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvs67680");
  script_xref(name:"CISCO-SA", value:"cisco-sa-telepresence-path-tr-wdrnYEZZ");
  script_xref(name:"IAVA", value:"2020-A-0055");

  script_name(english:"Cisco TelePresence Endpoint Software Path Traversal (cisco-sa-telepresence-path-tr-wdrnYEZZ)");
  script_summary(english:"Checks the version of Cisco TelePresence Software");

  script_set_attribute(attribute:"synopsis", value:
"The remote device is missing a vendor-supplied security patch");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version, the Cisco TelePresence Codec (TC) and Collaboration Endpoint (CE) Cisco
TelePresence Software is affected by a directory traversal vulnerability. An authenticated, remote attacker can exploit
this vulnerability in order to read and write arbitrary files on the remote host.

Please see the included Cisco BIDs and Cisco Security Advisory for more information");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-telepresence-path-tr-wdrnYEZZ
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?86cc9a48");
  # https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs45241
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6b7ec8f6");
  # https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs67675
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?075eccb8");
  # https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs67680
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2c33b8fc");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID CSCvs67675 or CSCvs45241 and CSCvs67680");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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:L/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:"cvss_score_source", value:"CVE-2019-15288");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/01/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/01/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/02/07");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:telepresence_tc_software");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:telepresence_ce");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"CISCO");

  script_copyright(english:"This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_telepresence_mcu_detect.nasl");
  script_require_keys("Cisco/TelePresence_MCU/Device", "Cisco/TelePresence_MCU/Version");

  exit(0);
}

include('audit.inc');
include('global_settings.inc');
include('misc_func.inc');

app_name = 'Cisco TelePresence TC/CE software';
version = get_kb_item_or_exit('Cisco/TelePresence_MCU/Version');
bugid = '';

short_version = pregmatch(pattern: "^(TC|ce)(\d+(?:\.\d+){0,2})", string:version);
if (isnull(short_version))
  audit(AUDIT_NOT_DETECT, app_name);
else
{
  short_type = short_version[1];
  short_num = short_version[2];
}

fix = '';

if (short_type == 'TC'){
    fix = '7.3.20';
    bugid = 'CSCvs67675';
}
else if (short_type == 'ce'){
  bugid = 'CSCvs45241, CSCvs67680';
  if (short_num =~ "^8\.")
    fix = '8.3.8';
  else if (short_num =~ "^9\.[0-8]($|[^0-9])")
    fix = '9.8.3';
  else if (short_num =~ "^9\.9")
    fix = '9.9.2';
}
else audit(AUDIT_NOT_DETECT, app_name);

if (!empty_or_null(fix) && ver_compare(ver:short_num, fix:fix, strict:FALSE) < 0)
{
  report = '\n  Installed Version : ' + version +
           '\n  Cisco Bug ID      : ' + bugid +
           '\n';

  security_report_v4(port:0, severity:SECURITY_HOLE, extra:report);
}
else audit(AUDIT_INST_VER_NOT_VULN, app_name, version);