Vulnerabilities > CVE-2013-7093 - Improper Authentication vulnerability in SAP Network Interface Router 39.3

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
PARTIAL
Availability impact
NONE
network
low complexity
sap
CWE-287
nessus

Summary

SAP Network Interface Router (SAProuter) 39.3 SP4 allows remote attackers to bypass authentication and modify the configuration via unspecified vectors.

Vulnerable Configurations

Part Description Count
Application
Sap
1

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 familyGeneral
NASL idSAP_ROUTER_NOTE1853140.NASL
descriptionThe remote host has a version of SAProuter that is affected by an authentication bypass vulnerability. When started with the
last seen2020-06-01
modified2020-06-02
plugin id72263
published2014-02-03
reporterThis script is Copyright (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/72263
titleSAProuter Remote Authentication Bypass (Note 1853140)
code
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(72263);
  script_version("1.7");
  script_cvs_date("Date: 2019/11/26");

  script_cve_id("CVE-2013-7093");
  script_bugtraq_id(64230);

  script_name(english:"SAProuter Remote Authentication Bypass (Note 1853140)");
  script_summary(english:"Attempts to request information from SAProuter.");

  script_set_attribute(attribute:"synopsis", value:
"The remote application is susceptible to an authentication bypass
attack.");
  script_set_attribute(attribute:"description", value:
"The remote host has a version of SAProuter that is affected by an
authentication bypass vulnerability. When started with the '-X' flag,
SAProuter permits routing to itself given a 'saprouttab' that allows
access to its port. An unauthenticated, remote attacker can issue
commands to SAProuter.");
  script_set_attribute(attribute:"see_also", value:"https://service.sap.com/sap/support/notes/1853140");
  # https://erpscan.com/advisories/erpscan-13-023-saprouter-authentication-bypass/
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?6db5b37c");
  script_set_attribute(attribute:"solution", value:
"Restart SAProuter without '-X' and review the permissions in
'saprouttab'.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2013/11/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2014/02/03");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:sap:network_interface_router");
  script_end_attributes();

  script_category(ACT_ATTACK);
  script_family(english:"General");

  script_copyright(english:"This script is Copyright (C) 2014-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("sap_router_detect.nbin");
  script_require_keys("Services/sap_router");

  exit(0);
}

include("audit.inc");
include("byte_func.inc");
include("global_settings.inc");
include("misc_func.inc");

# Find the port from the KB.
port = get_service(svc:"sap_router", default:3299, exit_on_fail:TRUE);

# Pull the version from the KB.
ver = get_kb_item_or_exit("sap/router/" + port + "/ver");
if (ver !~ "^[0-9]+(\.[0-9]+( \(SP[0-9]+\))?)*$") audit(AUDIT_NONNUMERIC_VER, "SAProuter", port, ver);
ver = split(ver, sep:".", keep:FALSE);
ver = int(ver[0]);

if( ver !~ "^39\." && ver !~ "^40\.")
  audit(AUDIT_LISTEN_NOT_VULN, "SAProuter", port, ver);

# Open a socket.
soc = open_sock_tcp(port);
if (!soc) audit(AUDIT_SOCK_FAIL, port);

# All parameters are big-endian.
set_byte_order(BYTE_ORDER_BIG_ENDIAN);

# Create a request packet for a '-l' (router info).
req = raw_string(
  0, 0, 0, 15,    # Length of body
  'ROUTER_ADM\0', # Request type (admin)
  ver,            # Client major version
  2,              # Opcode (info request)
  0, 0            # Padding
);

# Send the request.
send(socket:soc, data:req);

# The response will be some number of length-prefixed messages,
# containing either ASCII or binary lines. We don't know the full
# packet format, so a useful heuristic is that when we're successful,
# we'll get multiple responses many of which are null-terminated
# strings.
#
# The final message is empty, just a dword of null bytes for length.
info = "";
while (TRUE)
{
  # Get the length of the response.
  res = recv(socket:soc, min:4, length:4);
  len = getdword(blob:res);
  if (!len)
    break;

  # Get the body of the response.
  res = recv(socket:soc, min:len, length:len);
  if (strlen(res) != len)
    break;

  # Check for an error.
  if ("NI_RTERR" >< res)
  {
    info = "";
    break;
  }

  # If the response contains only printable characters and is
  # null-terminated, then keep it.
  res = str_replace(string:res, find:'\n', replace:'');
  if (res =~ "^[\x20-\x7E]+.$")
    info += '\n  ' + substr(res, 0, strlen(res) - 2);
}

close(soc);

if (!info) audit(AUDIT_LISTEN_NOT_VULN, "SAProuter", port);

report = NULL;
if (report_verbosity > 0)
{
  report =
    '\n' + 'Nessus was able to retrieve the following information from the'+
    '\n' + 'remote SAProuter by issuing an information request :' +
    '\n' +  info +
    '\n';
}

security_warning(port:port, extra:report);