Vulnerabilities > CVE-2001-0537 - Improper Authentication vulnerability in Cisco IOS
Attack vector
UNKNOWN Attack complexity
UNKNOWN Privileges required
UNKNOWN Confidentiality impact
UNKNOWN Integrity impact
UNKNOWN Availability impact
UNKNOWN Summary
HTTP server for Cisco IOS 11.3 to 12.2 allows attackers to bypass authentication and execute arbitrary commands, when local authorization is being used, by specifying a high access level in the URL.
Vulnerable Configurations
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.
Exploit-Db
description Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability (3). CVE-2001-0537 . Remote exploit for hardware platform id EDB-ID:20977 last seen 2016-02-02 modified 2001-03-07 published 2001-03-07 reporter hypoclear source https://www.exploit-db.com/download/20977/ title Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability 3 description Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability (4). CVE-2001-0537 . Remote exploit for hardware platform id EDB-ID:20978 last seen 2016-02-02 modified 2001-06-27 published 2001-06-27 reporter blackangels source https://www.exploit-db.com/download/20978/ title Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability 4 description Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability (2). CVE-2001-0537 . Remote exploit for hardware platform id EDB-ID:20976 last seen 2016-02-02 modified 2001-06-27 published 2001-06-27 reporter Eliel C. Sardanons source https://www.exploit-db.com/download/20976/ title Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability 2 description Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability (1). CVE-2001-0537 . Remote exploit for hardware platform id EDB-ID:20975 last seen 2016-02-02 modified 2001-06-27 published 2001-06-27 reporter cronos source https://www.exploit-db.com/download/20975/ title Cisco IOS 11.x/12.x HTTP Configuration Arbitrary Administrative Access Vulnerability 1
Metasploit
description | This module exploits a vulnerability in the Cisco IOS HTTP Server. By sending a GET request for "/level/num/exec/..", where num is between 16 and 99, it is possible to bypass authentication and obtain full system control. IOS 11.3 -> 12.2 are reportedly vulnerable. This module tested successfully against a Cisco 1600 Router IOS v11.3(11d). |
id | MSF:AUXILIARY/SCANNER/HTTP/CISCO_IOS_AUTH_BYPASS |
last seen | 2020-04-11 |
modified | 2017-11-08 |
published | 2010-12-10 |
references | https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2001-0537 |
reporter | Rapid7 |
source | https://github.com/rapid7/metasploit-framework/blob/master//modules/auxiliary/scanner/http/cisco_ios_auth_bypass.rb |
title | Cisco IOS HTTP Unauthorized Administrative Access |
Nessus
NASL family CISCO NASL id CISCO_HTTP_ADMIN_ACCESS.NASL description It is possible to execute arbitrary commands on the remote Cisco router. An attacker may leverage this issue to disable network access via this device or lock legitimate users out of the router. last seen 2020-06-01 modified 2020-06-02 plugin id 10700 published 2001-07-02 reporter This script is Copyright (C) 2001-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/10700 title Cisco IOS HTTP Configuration Unauthorized Administrative Access code # # (C) Tenable Network Security, Inc. # include("compat.inc"); if(description) { script_id(10700); script_version ("1.38"); script_cve_id("CVE-2001-0537"); script_bugtraq_id(2936); script_name(english:"Cisco IOS HTTP Configuration Unauthorized Administrative Access"); script_set_attribute(attribute:"synopsis", value: "The remote router allows authentication to be bypassed and arbitrary commands to be executed." ); script_set_attribute(attribute:"description", value: "It is possible to execute arbitrary commands on the remote Cisco router. An attacker may leverage this issue to disable network access via this device or lock legitimate users out of the router." ); # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20010627-ios-http-level script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?dba2bf4f" ); script_set_attribute(attribute:"solution", value: "Disable the web configuration interface completely." ); script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C"); 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_cwe_id(287); script_set_attribute(attribute:"plugin_publication_date", value: "2001/07/02"); script_cvs_date("Date: 2018/11/15 20:50:20"); script_set_attribute(attribute:"vuln_publication_date", value: "2001/06/27"); script_set_attribute(attribute:"patch_publication_date", value: "2001/06/27"); script_set_attribute(attribute:"plugin_type", value:"remote"); script_set_attribute(attribute:"cpe",value:"cpe:/o:cisco:ios"); script_set_attribute(attribute:"exploited_by_nessus", value:"true"); script_end_attributes(); script_summary(english:"Obtains the remote router configuration"); script_category(ACT_GATHER_INFO); script_copyright(english:"This script is Copyright (C) 2001-2018 Tenable Network Security, Inc."); script_family(english:"CISCO"); script_dependencie("http_version.nasl"); script_require_ports("Services/www", 80); exit(0); } # include("global_settings.inc"); include("misc_func.inc"); include("http.inc"); port = get_http_port(default:80); kb = get_kb_item("www/no404/" + port); banner = get_http_banner(port:port); if ( ! banner ) exit(0); if ( "cisco-IOS" >!< banner && !egrep(pattern:"level [0-9]+ access", string:banner)) exit(0); if ( ! isnull(kb) ) exit(0); if(get_port_state(port)) { for(i=16;i<100;i=i+1) { url = string("/level/", i, "/exec/show/config/cr"); res = http_send_recv3(method:"GET", item:url, port:port); if (isnull(res)) exit(0); if ( "enable" >< res[2] && "interface" >< res[2] && "ip address" >< res[2] ) { info = string( "\n", "Nessus was able to execute a command on the remote Cisco router and\n", "retrieve its configuration file using the following URL :\n", "\n", " ", build_url(port:port, qs:url), "\n", "\n", "Here are its contents :\n", "\n", res[2] ); security_hole(port:port, extra:info); exit(0); } } }
NASL family CISCO NASL id CISCO-SA-20010627-IOS-HTTP-LEVELHTTP.NASL description When the HTTP server is enabled and local authorization is used, it is possible, under some circumstances, to bypass the authentication and execute any command on the device. In that case, the user will be able to exercise complete control over the device. All commands will be executed with the highest privilege (level 15). All releases of Cisco IOS software, starting with release 11.3 and later, are vulnerable. Virtually all mainstream Cisco routers and switches running Cisco IOS software are affected by this vulnerability. Products that are not running Cisco IOS software are not vulnerable. The workaround for this vulnerability is to disable HTTP server on the router or to use Terminal Access Controller Access Control System (TACACS+) or Radius for authentication. last seen 2020-06-01 modified 2020-06-02 plugin id 48956 published 2010-09-01 reporter This script is (C) 2010-2018 Tenable Network Security, Inc. source https://www.tenable.com/plugins/nessus/48956 title IOS HTTP Authorization Vulnerability - Cisco Systems
Saint
bid | 2936 |
description | Cisco IOS HTTP access level authentication bypass |
id | net_cisco_webbypass |
osvdb | 578 |
title | cisco_ios_http_level |
type | remote |
References
- http://www.cisco.com/warp/public/707/IOS-httplevel-pub.html
- http://www.cert.org/advisories/CA-2001-14.html
- http://www.securityfocus.com/bid/2936
- http://www.ciac.org/ciac/bulletins/l-106.shtml
- http://www.osvdb.org/578
- https://exchange.xforce.ibmcloud.com/vulnerabilities/6749
- http://www.securityfocus.com/archive/1/4.3.2.7.2.20010629095801.0c3e6a70%40brussels.cisco.com
- http://www.securityfocus.com/archive/1/20010703011650.60515.qmail%40web14910.mail.yahoo.com
- http://www.securityfocus.com/archive/1/1601227034.20010702112207%40olympos.org
- http://www.securityfocus.com/archive/1/Pine.LNX.3.96.1010702134611.22995B-100000%40Lib-Vai.lib.asu.edu