Vulnerabilities > CVE-2015-6429 - Data Processing Errors vulnerability in Cisco IOS and IOS XE
Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
PARTIAL 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.
Vulnerable Configurations
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 family CISCO NASL id CISCO-SN-CSCUW08236-IOS.NASL description 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. last seen 2020-06-01 modified 2020-06-02 plugin id 87820 published 2016-01-08 reporter This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/87820 title Cisco 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 family CISCO NASL id CISCO-SN-CSCUW08236-IOSXE.NASL description According 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 seen 2020-06-01 modified 2020-06-02 plugin id 87821 published 2016-01-08 reporter This script is Copyright (C) 2016-2019 and is owned by Tenable, Inc. or an Affiliate thereof. source https://www.tenable.com/plugins/nessus/87821 title Cisco IOS XE Software IKEv1 State Machine DoS (CSCuw08236)