Vulnerabilities > CVE-2020-3194 - Improper Input Validation vulnerability in Cisco products

047910
CVSS 9.3 - CRITICAL
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
cisco
CWE-20
critical
nessus

Summary

A vulnerability in Cisco Webex Network Recording Player for Microsoft Windows and Cisco Webex Player for Microsoft Windows could allow an attacker to execute arbitrary code on an affected system. The vulnerability exists due to insufficient validation of certain elements with a Webex recording stored in either the Advanced Recording Format (ARF) or the Webex Recording Format (WRF). An attacker could exploit this vulnerability by sending a user a malicious ARF or WRF file through a link or email attachment and persuading the user to open the file with the affected software on the local system. A successful exploit could allow the attacker to execute arbitrary code on the affected system with the privileges of the targeted user.

Vulnerable Configurations

Part Description Count
Application
Cisco
108

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Buffer Overflow via Environment Variables
    This attack pattern involves causing a buffer overflow through manipulation of environment variables. Once the attacker finds that they can modify an environment variable, they may try to overflow associated buffers. This attack leverages implicit trust often placed in environment variables.
  • Server Side Include (SSI) Injection
    An attacker can use Server Side Include (SSI) Injection to send code to a web application that then gets executed by the web server. Doing so enables the attacker to achieve similar results to Cross Site Scripting, viz., arbitrary code execution and information disclosure, albeit on a more limited scale, since the SSI directives are nowhere near as powerful as a full-fledged scripting language. Nonetheless, the attacker can conveniently gain access to sensitive files, such as password files, and execute shell commands.
  • Cross Zone Scripting
    An attacker is able to cause a victim to load content into their web-browser that bypasses security zone controls and gain access to increased privileges to execute scripting code or other web objects such as unsigned ActiveX controls or applets. This is a privilege elevation attack targeted at zone-based web-browser security. In a zone-based model, pages belong to one of a set of zones corresponding to the level of privilege assigned to that page. Pages in an untrusted zone would have a lesser level of access to the system and/or be restricted in the types of executable content it was allowed to invoke. In a cross-zone scripting attack, a page that should be assigned to a less privileged zone is granted the privileges of a more trusted zone. This can be accomplished by exploiting bugs in the browser, exploiting incorrect configuration in the zone controls, through a cross-site scripting attack that causes the attackers' content to be treated as coming from a more trusted page, or by leveraging some piece of system functionality that is accessible from both the trusted and less trusted zone. This attack differs from "Restful Privilege Escalation" in that the latter correlates to the inadequate securing of RESTful access methods (such as HTTP DELETE) on the server, while cross-zone scripting attacks the concept of security zones as implemented by a browser.
  • Cross Site Scripting through Log Files
    An attacker may leverage a system weakness where logs are susceptible to log injection to insert scripts into the system's logs. If these logs are later viewed by an administrator through a thin administrative interface and the log data is not properly HTML encoded before being written to the page, the attackers' scripts stored in the log will be executed in the administrative interface with potentially serious consequences. This attack pattern is really a combination of two other attack patterns: log injection and stored cross site scripting.
  • Command Line Execution through SQL Injection
    An attacker uses standard SQL injection methods to inject data into the command line for execution. This could be done directly through misuse of directives such as MSSQL_xp_cmdshell or indirectly through injection of data into the database that would be interpreted as shell commands. Sometime later, an unscrupulous backend application (or could be part of the functionality of the same application) fetches the injected data stored in the database and uses this data as command line arguments without performing proper validation. The malicious data escapes that data plane by spawning new commands to be executed on the host.

Nessus

NASL familyWindows
NASL idCISCO-SA-WEBEX-PLAYER-Q7RTGVBY.NASL
descriptionThe version of Cisco Webex Network Recording Player and Cisco Webex Player installed on the remote host is affected by a remote code execution vulnerability due to insufficient validation of certain elements within a Webex recording that is stored in either the Advanced Recording Format (ARF) or the Webex Recording Format (WRF). An unauthenticated remote attacker could exploit this, by sending a malicious ARF or WRF file to a user through a link or email attachment and persuading the user to open the file on the local system to execute arbitrary code with the same privileges of the targeted user. Please see the included Cisco BIDs and Cisco Security Advisory for more information.
last seen2020-05-03
modified2020-04-30
plugin id136120
published2020-04-30
reporterThis script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/136120
titleCisco Webex Network Recording Player and Cisco Webex Player Arbitrary Code Execution Vulnerability (cisco-sa-webex-player-Q7Rtgvby)
code
#
# (C) Tenable Network Security, Inc.
#

include('compat.inc');

if (description)
{
  script_id(136120);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/05/01");

  script_cve_id("CVE-2020-3194");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvs56936");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvs56937");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvs56938");
  script_xref(name:"CISCO-SA", value:"cisco-sa-webex-player-Q7Rtgvby");
  script_xref(name:"IAVA", value:"2020-A-0182");

  script_name(english:"Cisco Webex Network Recording Player and Cisco Webex Player Arbitrary Code Execution Vulnerability (cisco-sa-webex-player-Q7Rtgvby)");

  script_set_attribute(attribute:"synopsis", value:
"The video player installed on the remote Windows host is affected by a remote code execution vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of Cisco Webex Network Recording Player and Cisco Webex Player installed on the remote host is affected by 
a remote code execution vulnerability due to insufficient validation of certain elements within a Webex recording that 
is stored in either the Advanced Recording Format (ARF) or the Webex Recording Format (WRF). An unauthenticated remote 
attacker could exploit this, by sending a malicious ARF or WRF file to a user through a link or email attachment and 
persuading the user to open the file on the local system to execute arbitrary code with the same privileges of the 
targeted user. Please see the included Cisco BIDs and Cisco Security Advisory for more information.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-webex-player-Q7Rtgvby
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ffb021db");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs56936");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs56937");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs56938");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCvs56936, CSCvs56937, CSCvs56938");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:L/AC:L/PR:N/UI:R/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-2020-3194");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_cwe_id(119);

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/04/15");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/04/30");

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

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

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

  script_dependencies("webex_player_installed.nasl");
  script_require_keys("installed_sw/WebEx ARF/WRF Player");
  script_require_ports(139, 445);

  exit(0);
}

include('vcf.inc');

app = 'WebEx ARF/WRF Player';
app_info = vcf::get_app_info(app:app);

constraints = [
     {'min_version': '39.5',  'fixed_version' : '39.5.18' },
     {'min_version': '40',  'fixed_version' : '40.2' }
];

vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_HOLE);