Vulnerabilities > CVE-2017-6655 - Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in Cisco products

047910
CVSS 6.5 - MEDIUM
Attack vector
ADJACENT_NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
HIGH
low complexity
cisco
CWE-119
nessus
NVD
Published: 2017-06-13
Updated: 2024-11-21

Summary

A vulnerability in the Fibre Channel over Ethernet (FCoE) protocol implementation in Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition when an FCoE-related process unexpectedly reloads. This vulnerability affects Cisco NX-OS Software on the following Cisco devices when they are configured for FCoE: Multilayer Director Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches. More Information: CSCvc91729. Known Affected Releases: 8.3(0)CV(0.833). Known Fixed Releases: 8.3(0)ISH(0.62) 8.3(0)CV(0.944) 8.1(1) 8.1(0.8)S0 7.3(2)D1(0.47).

Vulnerable Configurations

Part Description Count
Application
Cisco
4
OS
Cisco
2

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.
  • Overflow Buffers
    Buffer Overflow attacks target improper or missing bounds checking on buffer operations, typically triggered by input injected by an attacker. As a consequence, an attacker is able to write past the boundaries of allocated buffer regions in memory, causing a program crash or potentially redirection of execution as per the attackers' choice.
  • Client-side Injection-induced Buffer Overflow
    This type of attack exploits a buffer overflow vulnerability in targeted client software through injection of malicious content from a custom-built hostile service.
  • Filter Failure through Buffer Overflow
    In this attack, the idea is to cause an active filter to fail by causing an oversized transaction. An attacker may try to feed overly long input strings to the program in an attempt to overwhelm the filter (by causing a buffer overflow) and hoping that the filter does not fail securely (i.e. the user input is let into the system unfiltered).
  • MIME Conversion
    An attacker exploits a weakness in the MIME conversion routine to cause a buffer overflow and gain control over the mail server machine. The MIME system is designed to allow various different information formats to be interpreted and sent via e-mail. Attack points exist when data are converted to MIME compatible format and back.

Nessus

NASL familyCISCO
NASL idCISCO-SA-20170607-NXOS.NASL
descriptionAccording to its version and configuration, the Cisco NX-OS software running on the remote device is affected by a denial of service vulnerability in the Fibre Channel over Ethernet (FCoE) protocol implementation due to improper padding validation of FCoE frames. An unauthenticated, adjacent attacker can exploit this, via a stream of specially crafted FCoE packets, to cause an FCoE-related process to unexpectedly reload, thereby impacting FCoE traffic passing through the device.
last seen2020-06-01
modified2020-06-02
plugin id100840
published2017-06-16
reporterThis script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
sourcehttps://www.tenable.com/plugins/nessus/100840
titleCisco NX-OS Fibre Channel over Ethernet DoS (cisco-sa-20170607-nxos)
code
#TRUSTED 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
#
# (C) Tenable Network Security, Inc.
#

include("compat.inc");

if (description)
{
  script_id(100840);
  script_version("1.8");
  script_cvs_date("Date: 2019/11/13");

  script_cve_id("CVE-2017-6655");
  script_bugtraq_id(98991);
  script_xref(name:"CISCO-BUG-ID", value:"CSCvc91729");
  script_xref(name:"CISCO-SA", value:"cisco-sa-20170607-nxos");
  script_xref(name:"IAVB", value:"2017-B-0072");

  script_name(english:"Cisco NX-OS Fibre Channel over Ethernet DoS (cisco-sa-20170607-nxos)");
  script_summary(english:"Checks the NX-OS version.");

  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 version and configuration, the Cisco NX-OS software
running on the remote device is affected by a denial of service
vulnerability in the Fibre Channel over Ethernet (FCoE) protocol
implementation due to improper padding validation of FCoE frames. An
unauthenticated, adjacent attacker can exploit this, via a stream of
specially crafted FCoE packets, to cause an FCoE-related process to
unexpectedly reload, thereby impacting FCoE traffic passing through
the device.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170607-nxos
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0e150b33");
  script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvc91729");
  script_set_attribute(attribute:"solution", value:
"Upgrade to the relevant fixed version referenced in Cisco bug ID
CSCvc91729.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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-2017-6655");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/06/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/16");

  script_set_attribute(attribute:"plugin_type", value:"combined");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nx-os");
  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) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("cisco_nxos_version.nasl");
  script_require_keys("Host/Cisco/NX-OS/Version", "Host/Cisco/NX-OS/Device", "Host/Cisco/NX-OS/Model");

  exit(0);
}

include("audit.inc");
include("cisco_func.inc");
include("cisco_kb_cmd_func.inc");

device  = get_kb_item_or_exit("Host/Cisco/NX-OS/Device");
model   = get_kb_item_or_exit("Host/Cisco/NX-OS/Model");
version = get_kb_item_or_exit("Host/Cisco/NX-OS/Version");

flag = FALSE;
cbid = "CSCvc91729";

# Only affects Nexus
if (device != 'Nexus')
  audit(AUDIT_HOST_NOT, "affected");

# 7000 series
if (model =~ "^7[0-9][0-9][0-9]([^0-9]|$)")
{
  if (version == "8.0(1)S2" || version == "8.3(0)CV(0.833)")
    flag = TRUE;
}

# 7700 series
if (model =~ "^77[0-9][0-9]([^0-9]|$)")
{
  if (version == "8.0(1)(ED)")
    flag = TRUE;
}

if (flag && get_kb_item("Host/local_checks_enabled"))
{
  flag = FALSE;

  # check if fcoe is enabled
  buf = cisco_command_kb_item("Host/Cisco/Config/show feature-set fcoe", "show feature-set fcoe");
  if (check_cisco_result(buf))
  {
    if ("enabled" >< buf)
      flag = TRUE;
  }
  else if (cisco_needs_enable(buf)) override = TRUE;
}

if (flag || override)
{
  security_report_cisco(
    port     : 0,
    severity : SECURITY_NOTE,
    override : override,
    version  : version,
    bug_id   : cbid
  );
}
else audit(AUDIT_HOST_NOT, "affected");

References