Vulnerabilities > CVE-2016-1387 - Improper Authentication vulnerability in Cisco Telepresence TC Software

047910
CVSS 9.8 - CRITICAL
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
HIGH
Integrity impact
HIGH
Availability impact
HIGH
network
low complexity
cisco
CWE-287
critical
nessus

Summary

The XML API in TelePresence Codec (TC) 7.2.0, 7.2.1, 7.3.0, 7.3.1, 7.3.2, 7.3.3, 7.3.4, and 7.3.5 and Collaboration Endpoint (CE) 8.0.0, 8.0.1, and 8.1.0 in Cisco TelePresence Software mishandles authentication, which allows remote attackers to execute control commands or make configuration changes via an API request, aka Bug ID CSCuz26935.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • Authentication Abuse
    An attacker obtains unauthorized access to an application, service or device either through knowledge of the inherent weaknesses of an authentication mechanism, or by exploiting a flaw in the authentication scheme's implementation. In such an attack an authentication mechanism is functioning but a carefully controlled sequence of events causes the mechanism to grant access to the attacker. This attack may exploit assumptions made by the target's authentication procedures, such as assumptions regarding trust relationships or assumptions regarding the generation of secret values. This attack differs from Authentication Bypass attacks in that Authentication Abuse allows the attacker to be certified as a valid user through illegitimate means, while Authentication Bypass allows the user to access protected material without ever being certified as an authenticated user. This attack does not rely on prior sessions established by successfully authenticating users, as relied upon for the "Exploitation of Session Variables, Resource IDs and other Trusted Credentials" attack patterns.
  • Exploiting Trust in Client (aka Make the Client Invisible)
    An attack of this type exploits a programs' vulnerabilities in client/server communication channel authentication and data integrity. It leverages the implicit trust a server places in the client, or more importantly, that which the server believes is the client. An attacker executes this type of attack by placing themselves in the communication channel between client and server such that communication directly to the server is possible where the server believes it is communicating only with a valid client. There are numerous variations of this type of attack.
  • Utilizing REST's Trust in the System Resource to Register Man in the Middle
    This attack utilizes a REST(REpresentational State Transfer)-style applications' trust in the system resources and environment to place man in the middle once SSL is terminated. Rest applications premise is that they leverage existing infrastructure to deliver web services functionality. An example of this is a Rest application that uses HTTP Get methods and receives a HTTP response with an XML document. These Rest style web services are deployed on existing infrastructure such as Apache and IIS web servers with no SOAP stack required. Unfortunately from a security standpoint, there frequently is no interoperable identity security mechanism deployed, so Rest developers often fall back to SSL to deliver security. In large data centers, SSL is typically terminated at the edge of the network - at the firewall, load balancer, or router. Once the SSL is terminated the HTTP request is in the clear (unless developers have hashed or encrypted the values, but this is rare). The attacker can utilize a sniffer such as Wireshark to snapshot the credentials, such as username and password that are passed in the clear once SSL is terminated. Once the attacker gathers these credentials, they can submit requests to the web service provider just as authorized user do. There is not typically an authentication on the client side, beyond what is passed in the request itself so once this is compromised, then this is generally sufficient to compromise the service's authentication scheme.
  • Man in the Middle Attack
    This type of attack targets the communication between two components (typically client and server). The attacker places himself in the communication channel between the two components. Whenever one component attempts to communicate with the other (data flow, authentication challenges, etc.), the data first goes to the attacker, who has the opportunity to observe or alter it, and it is then passed on to the other component as if it was never intercepted. This interposition is transparent leaving the two compromised components unaware of the potential corruption or leakage of their communications. The potential for Man-in-the-Middle attacks yields an implicit lack of trust in communication or identify between two components.

Nessus

NASL familyCISCO
NASL idCISCO-SA-20160504-TPXML.NASL
descriptionThe remote host is running a version of Cisco TelePresence Codec (TC) that is 7.2.x prior to 7.3.6 or a version of Cisco Collaboration Endpoint (CE) software that is 8.x prior 8.1.1. It is, therefore, affected by an authentication bypass vulnerability in the XML application programming interface (API) of Cisco TC or Cisco CE due to improper implementation of authentication mechanisms for the XML API. An unauthenticated, remote attacker can exploit this, via a crafted HTTP request to the XML API, to bypass authentication and perform unauthorized configuration changes or issue control commands.
last seen2020-06-01
modified2020-06-02
plugin id91130
published2016-05-13
reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/91130
titleCisco TelePresence XML API HTTP Request Handling Authentication Bypass (cisco-sa-20160504-tpxml)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(91130);
  script_version("1.6");
  script_cvs_date("Date: 2019/11/19");

  script_cve_id("CVE-2016-1387");
  script_xref(name:"CISCO-BUG-ID", value:"CSCuz26935");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20160504-tpxml");

  script_name(english:"Cisco TelePresence XML API HTTP Request Handling Authentication Bypass (cisco-sa-20160504-tpxml)");
  script_summary(english:"Checks the software version.");

  script_set_attribute(attribute:"synopsis", value:
"The remote host is missing a vendor-supplied security patch.");
  script_set_attribute(attribute:"description", value:
"The remote host is running a version of Cisco TelePresence Codec (TC)
that is 7.2.x prior to 7.3.6 or a version of Cisco Collaboration
Endpoint (CE) software that is 8.x prior 8.1.1. It is, therefore,
affected by an authentication bypass vulnerability in the XML
application programming interface (API) of Cisco TC or Cisco CE due to
improper implementation of authentication mechanisms for the XML API.
An unauthenticated, remote attacker can exploit this, via a crafted
HTTP request to the XML API, to bypass authentication and perform
unauthorized configuration changes or issue control commands.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20160504-tpxml
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a4e80bb3");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Cisco TelePresence Codec (TC) version 7.3.6 or Cisco
Collaboration Endpoint (CE) version 8.1.1. Alternatively, apply the
workaround referenced in the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:N/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-2016-1387");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/05/04");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/05/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/05/13");

  script_set_attribute(attribute:"potential_vulnerability", value:"true");
  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:telepresence_tc_software");
  script_set_attribute(attribute:"cpe", value:"x-cpe:/a:cisco:telepresence_ce_software");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2016-2019 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";
device = get_kb_item_or_exit("Cisco/TelePresence_MCU/Device");
version = get_kb_item_or_exit("Cisco/TelePresence_MCU/Version");
flag = FALSE;

# Affected models:
# TelePresence EX Series
# TelePresence Integrator C Series
# TelePresence MX Series
# TelePresence Profile Series
# TelePresence SX Series
# TelePresence SX Quick Set Series
# TelePresence VX Clinical Assistant
# TelePresence VX Tactical
# Note: VX Tactical/Clinical identify as SX20
if (
  device !~ " C[2469]0($|[ \n\r])" &&
  device !~ " EX[69]0($|[ \n\r])" &&
  device !~ " MX[2378]00(\sG2)?($|[ \n\r])" &&
  device !~ " Profile.+($|[ \n\r])" &&
  device !~ " SX[128]0($|[ \n\r])"
) audit(AUDIT_HOST_NOT, "an affected Cisco TelePresence device");

# Based on headers returned during testing/research, TC is upper-case
# and ce is lowercase in the SoftW: section of the header. 
short_version = eregmatch(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];
}

if(short_type == "TC"){
  if (short_num =~ "^7(\.3)?$") audit(AUDIT_VER_NOT_GRANULAR, app_name, version);
  if (short_num =~ "^7\.[23]" && ver_compare(ver:short_num, fix:'7.3.6', strict:FALSE) < 0)
    flag = TRUE;
}
else if (short_type == "ce"){
  if (short_num =~ "^8(\.1)?$") audit(AUDIT_VER_NOT_GRANULAR, app_name, version);
  if (short_num =~ "^8\." && ver_compare(ver:short_num, fix:'8.1.1', strict:FALSE) < 0)
    flag = TRUE;
}
else audit(AUDIT_NOT_DETECT, app_name);

if (flag)
{
  # Paranoid because we can't be sure XML API is running
  # or isn't disabled, as per workaround in advisory
  if (report_paranoia < 2) audit(AUDIT_PARANOID);

  port = 0;

  report = '\n  Detected version : ' + version +
           '\n  Fixed version    : See solution.' +
           '\n  Cisco bug ID     : CSCuz26935' +
           '\n';

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