Vulnerabilities > CVE-2015-6429 - Data Processing Errors vulnerability in Cisco IOS and IOS XE

047910
CVSS 5.0 - MEDIUM
Attack vector
NETWORK
Attack complexity
LOW
Privileges required
NONE
Confidentiality impact
NONE
Integrity impact
NONE
Availability impact
PARTIAL
network
low complexity
cisco
CWE-19
nessus

Summary

The IKEv1 state machine in Cisco IOS 15.4 through 15.6 and IOS XE 3.15 through 3.17 allows remote attackers to cause a denial of service (IPsec connection termination) via a crafted IKEv1 packet to a tunnel endpoint, aka Bug ID CSCuw08236.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • 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.
  • XML Nested Payloads
    Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. By nesting XML data and causing this data to be continuously self-referential, an attacker can cause the XML parser to consume more resources while processing, causing excessive memory consumption and CPU utilization. An attacker's goal is to leverage parser failure to his or her advantage. In most cases this type of an attack will result in a denial of service due to an application becoming unstable, freezing, or crash. However it may be possible to cause a crash resulting in arbitrary code execution, leading to a jump from the data plane to the control plane [R.230.1].
  • XML Oversized Payloads
    Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. By supplying oversized payloads in input vectors that will be processed by the XML parser, an attacker can cause the XML parser to consume more resources while processing, causing excessive memory consumption and CPU utilization, and potentially cause execution of arbitrary code. An attacker's goal is to leverage parser failure to his or her advantage. In many cases this type of an attack will result in a denial of service due to an application becoming unstable, freezing, or crash. However it is possible to cause a crash resulting in arbitrary code execution, leading to a jump from the data plane to the control plane [R.231.1].
  • XML Client-Side Attack
    Client applications such as web browsers that process HTML data often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. These adverse effects may include the parser crashing, consuming too much of a resource, executing too slowly, executing code supplied by an attacker, allowing usage of unintended system functionality, etc. An attacker's goal is to leverage parser failure to his or her advantage. In some cases it may be possible to jump from the data plane to the control plane via bad data being passed to an XML parser. [R.484.1]
  • XML Parser Attack
    Applications often need to transform data in and out of the XML format by using an XML parser. It may be possible for an attacker to inject data that may have an adverse effect on the XML parser when it is being processed. These adverse effects may include the parser crashing, consuming too much of a resource, executing too slowly, executing code supplied by an attacker, allowing usage of unintended system functionality, etc. An attacker's goal is to leverage parser failure to his or her advantage. In some cases it may be possible to jump from the data plane to the control plane via bad data being passed to an XML parser. [R.99.1]

Nessus

  • NASL familyCISCO
    NASL idCISCO-SN-CSCUW08236-IOS.NASL
    descriptionAccording to its self-reported version, the Cisco IOS software running on the remote device is affected by a denial of service vulnerability in the Internet Key Exchange version 1 (IKEv1) subsystem due to insufficient condition checks in the IKEv1 state machine. An unauthenticated, remote attacker can exploit this vulnerability, by sending a spoofed, specific IKEv1 packet to an endpoint of an IPsec tunnel, to tear down IPsec tunnels that terminate on the endpoint, resulting in a partial denial of service condition.
    last seen2020-06-01
    modified2020-06-02
    plugin id87820
    published2016-01-08
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/87820
    titleCisco IOS Software IKEv1 State Machine DoS (CSCuw08236)
    code
    #TRUSTED 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
    #
    # (C) Tenable Network Security, Inc.
    #
    
    include("compat.inc");
    
    if (description)
    {
      script_id(87820);
      script_version("1.10");
      script_cvs_date("Date: 2019/11/20");
    
      script_cve_id("CVE-2015-6429");
      script_bugtraq_id(79745);
      script_xref(name:"CISCO-BUG-ID", value:"CSCuw08236");
      script_xref(name:"CISCO-SA", value:"cisco-sa-20151218-ios");
    
      script_name(english:"Cisco IOS Software IKEv1 State Machine DoS (CSCuw08236)");
      script_summary(english:"Checks the IOS 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 self-reported version, the Cisco IOS software running
    on the remote device is affected by a denial of service vulnerability
    in the Internet Key Exchange version 1 (IKEv1) subsystem due to
    insufficient condition checks in the IKEv1 state machine. An
    unauthenticated, remote attacker can exploit this vulnerability, by
    sending a spoofed, specific IKEv1 packet to an endpoint of an IPsec
    tunnel, to tear down IPsec tunnels that terminate on the endpoint,
    resulting in a partial denial of service condition.");
      # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151218-ios
      script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1b10e25c");
      script_set_attribute(attribute:"see_also", value:"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuw08236");
      script_set_attribute(attribute:"solution", value:
    "Apply the relevant patch referenced in Cisco security advisory
    cisco-sa-20151218-ios.");
      script_set_cvss_base_vector("CVSS2#AV:N/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:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L");
      script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
    
      script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
    
      script_set_attribute(attribute:"vuln_publication_date", value:"2015/12/18");
      script_set_attribute(attribute:"patch_publication_date", value:"2015/12/18");
      script_set_attribute(attribute:"plugin_publication_date", value:"2016/01/08");
    
      script_set_attribute(attribute:"plugin_type", value:"local");
      script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:ios");
      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_ios_version.nasl");
      script_require_keys("Host/Cisco/IOS/Version");
    
      exit(0);
    }
    
    include("audit.inc");
    include("cisco_func.inc");
    include("cisco_kb_cmd_func.inc");
    
    flag = 0;
    override = 0;
    
    ver = get_kb_item_or_exit("Host/Cisco/IOS/Version");
    
    # Check for vuln versions
    if (
      ver == '15.4(3)S' ||
      ver == '15.5(3)M' ||
      ver == '15.5(3)M1' ||
      ver == '15.5(1)S' ||
      ver == '15.5(2)S' ||  # Maps to IOS XE 3.15.0S
      ver == '15.5(2)S1' || # Maps to IOS XE 3.15.1S
      ver == '15.5(2)S2' || # Maps to IOS XE 3.15.2S
      ver == '15.5(3)S' ||  # Maps to IOS XE 3.16.0S
      ver == '15.5(3)S1' || # Maps to IOS XE 3.16.1S
      ver == '15.5(1)T' ||
      ver == '15.5(2)T' ||
      ver == '15.6(1)S' ||  # Maps to IOS XE 3.17.0S
      ver == '15.6(1)S1' || # Maps to IOS XE 3.17.1S
      ver == '15.6(1)T0a'
    ) flag++;
    
    cmds = make_list();
    # Check that IKEv1 or ISAKMP is running
    if (flag && get_kb_item("Host/local_checks_enabled"))
    {
      pat = "(\d+.\d+.\d+.\d+|.*:.*|UNKNOWN|--any--)\s+(500|848|4500)\s";
    
      flag = 0;
      buf = cisco_command_kb_item("Host/Cisco/Config/show_ip_sockets","show ip sockets");
      if (check_cisco_result(buf))
      {
        if (
          preg(multiline:TRUE, pattern:pat, string:buf)
        )
        {
          flag = 1;
          cmds = make_list(cmds, "show ip sockets");
        }
      }
      else if (cisco_needs_enable(buf))
      {
        flag = 1;
        override = 1;
      }
    
      if (!flag)
      {
        buf = cisco_command_kb_item("Host/Cisco/Config/show_udp","show udp");
        if (check_cisco_result(buf))
        {
          if (
            preg(multiline:TRUE, pattern:pat, string:buf)
          )
          {
            flag = 1;
            cmds = make_list(cmds, "show udp");
          }
        }
        else if (cisco_needs_enable(buf))
        {
          flag = 1;
          override = 1;
        }
      }
    }
    
    if (flag)
    {
      security_report_cisco(
        port     : 0,
        severity : SECURITY_WARNING,
        override : override,
        version  : ver,
        bug_id   : "CSCuw08236",
        cmds     : cmds
      );
      exit(0);
    }
    else audit(AUDIT_HOST_NOT, "affected");
    
  • NASL familyCISCO
    NASL idCISCO-SN-CSCUW08236-IOSXE.NASL
    descriptionAccording to its self-reported version, the Cisco IOS XE software running on the remote device is affected by a denial of service vulnerability in the Internet Key Exchange version 1 (IKEv1) subsystem due to insufficient condition checks in the IKEv1 state machine. An unauthenticated, remote attacker can exploit this vulnerability, by sending a spoofed, specific IKEv1 packet to an endpoint of an IPsec tunnel, to tear down IPsec tunnels that terminate on the endpoint, resulting in a partial denial of service condition.
    last seen2020-06-01
    modified2020-06-02
    plugin id87821
    published2016-01-08
    reporterThis script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof.
    sourcehttps://www.tenable.com/plugins/nessus/87821
    titleCisco IOS XE Software IKEv1 State Machine DoS (CSCuw08236)