Vulnerabilities > CVE-2013-3093 - Cross-Site Request Forgery (CSRF) vulnerability in Asus products

047910
CVSS 9.3 - CRITICAL
Attack vector
NETWORK
Attack complexity
MEDIUM
Privileges required
NONE
Confidentiality impact
COMPLETE
Integrity impact
COMPLETE
Availability impact
COMPLETE
network
asus
CWE-352
critical

Summary

ASUS RT-N56U devices allow CSRF.

Common Weakness Enumeration (CWE)

Common Attack Pattern Enumeration and Classification (CAPEC)

  • JSON Hijacking (aka JavaScript Hijacking)
    An attacker targets a system that uses JavaScript Object Notation (JSON) as a transport mechanism between the client and the server (common in Web 2.0 systems using AJAX) to steal possibly confidential information transmitted from the server back to the client inside the JSON object by taking advantage of the loophole in the browser's Same Origin Policy that does not prohibit JavaScript from one website to be included and executed in the context of another website. An attacker gets the victim to visit his or her malicious page that contains a script tag whose source points to the vulnerable system with a URL that requests a response from the server containing a JSON object with possibly confidential information. The malicious page also contains malicious code to capture the JSON object returned by the server before any other processing on it can take place, typically by overriding the JavaScript function used to create new objects. This hook allows the malicious code to get access to the creation of each object and transmit the possibly sensitive contents of the captured JSON object to the attackers' server. There is nothing in the browser's security model to prevent the attackers' malicious JavaScript code (originating from attacker's domain) to set up an environment (as described above) to intercept a JSON object response (coming from the vulnerable target system's domain), read its contents and transmit to the attackers' controlled site. The same origin policy protects the domain object model (DOM), but not the JSON.
  • Cross-Domain Search Timing
    An attacker initiates cross domain HTTP / GET requests and times the server responses. The timing of these responses may leak important information on what is happening on the server. Browser's same origin policy prevents the attacker from directly reading the server responses (in the absence of any other weaknesses), but does not prevent the attacker from timing the responses to requests that the attacker issued cross domain. For GET requests an attacker could for instance leverage the "img" tag in conjunction with "onload() / onerror()" javascript events. For the POST requests, an attacker could leverage the "iframe" element and leverage the "onload()" event. There is nothing in the current browser security model that prevents an attacker to use these methods to time responses to the attackers' cross domain requests. The timing for these responses leaks information. For instance, if a victim has an active session with their online e-mail account, an attacker could issue search requests in the victim's mailbox. While the attacker is not able to view the responses, based on the timings of the responses, the attacker could ask yes / no questions as to the content of victim's e-mails, who the victim e-mailed, when, etc. This is but one example; There are other scenarios where an attacker could infer potentially sensitive information from cross domain requests by timing the responses while asking the right questions that leak information.
  • Cross Site Identification
    An attacker harvests identifying information about a victim via an active session that the victim's browser has with a social networking site. A victim may have the social networking site open in one tab or perhaps is simply using the "remember me" feature to keep his or her session with the social networking site active. An attacker induces a payload to execute in the victim's browser that transparently to the victim initiates a request to the social networking site (e.g., via available social network site APIs) to retrieve identifying information about a victim. While some of this information may be public, the attacker is able to harvest this information in context and may use it for further attacks on the user (e.g., spear phishing). In one example of an attack, an attacker may post a malicious posting that contains an image with an embedded link. The link actually requests identifying information from the social networking site. A victim who views the malicious posting in his or her browser will have sent identifying information to the attacker, as long as the victim had an active session with the social networking site. There are many other ways in which the attacker may get the payload to execute in the victim's browser mainly by finding a way to hide it in some reputable site that the victim visits. The attacker could also send the link to the victim in an e-mail and trick the victim into clicking on the link. This attack is basically a cross site request forgery attack with two main differences. First, there is no action that is performed on behalf of the user aside from harvesting information. So standard CSRF protection may not work in this situation. Second, what is important in this attack pattern is the nature of the data being harvested, which is identifying information that can be obtained and used in context. This real time harvesting of identifying information can be used as a prelude for launching real time targeted social engineering attacks on the victim.
  • Cross Site Request Forgery (aka Session Riding)
    An attacker crafts malicious web links and distributes them (via web pages, email, etc.), typically in a targeted manner, hoping to induce users to click on the link and execute the malicious action against some third-party application. If successful, the action embedded in the malicious link will be processed and accepted by the targeted application with the users' privilege level. This type of attack leverages the persistence and implicit trust placed in user session cookies by many web applications today. In such an architecture, once the user authenticates to an application and a session cookie is created on the user's system, all following transactions for that session are authenticated using that cookie including potential actions initiated by an attacker and simply "riding" the existing session cookie.

Packetstorm

data sourcehttps://packetstormsecurity.com/files/download/125345/asus-xssbypass.txt
idPACKETSTORM:125345
last seen2016-12-05
published2014-02-22
reporterHarry Sintonen
sourcehttps://packetstormsecurity.com/files/125345/ASUS-Router-Authentication-Bypass-Cross-Site-Scripting.html
titleASUS Router Authentication Bypass / Cross Site Scripting

Seebug

bulletinFamilyexploit
descriptionDescription ----------- Several ASUS routers include reflected Cross-Site Scripting (CWE-79) and authentication bypass (CWE-592) vulnerabilities. An attacker who can lure a victim to browse to a web site containing a specially crafted JavaScript payload can execute arbitrary commands on the router as administrator (root). No user interaction is required. Impact ------ An attacker can create a JavaScript payload that uses an exploit to unearth the administrative password from the victim's ASUS router and logs in to the device. Once logged in the payload can perform administrative actions, including arbitrary command execution as administrator (root). Details ------- The CSRF vulnerability CVE-2013-3093 discovered by Jacob Holcomb / Independent Security Evaluators (*) affecting various ASUS routers has been known for some time. The vulnerability enables an attacker to forge HTML forms and execute actions on the behalf of the target user (admin), enabling executing administrative functions. Another vulnerability allows executing arbitrary commands as administrator (root). ASUS was notified of these issues on March 29th 2013. These vulnerabilities were not considered critical, likely because of the seemingly strict prerequisites for the attack: "- The victim must have an active web application session on their ASUS router. - The victim must follow a link crafted by an attacker (e.g., by clicking the link directly, or through some other mechanism such as redirection from a malicious site). - The victim must have the necessary permissions to render and execute the forged HTTP." (*) http://securityevaluators.com/knowledge/case_studies/routers/Vulnerability_Catalog.pdf The two newly discovered vulnerabilities, described in more detail below, enable exploiting the earlier vulnerabilities in an automated fashion. The attack requires no interaction from the user, other than browsing to a website that has been injected with JavaScript code crafted by the attacker. The exploit could be embedded into various otherwise benign sites via e.g. malicious advertisement banners or by exploiting persistent Cross-Site Scripting vulnerabilities. The attacks could also be carried out with phishing email campaigns. The attack utilizes a reflected Cross-Site Scripting vulnerability on the unauthenticated error page to bypass the same-origin policy protection. Vulnerability number two described below is used to obtain the administrator's password. The reflected JavaScript payload executes within the context of the ASUS device and is able to utilize the CVE-2013-3093 CSRF vulnerability to perform actions on the behalf of the user (admin). The exploit utilizes the "SystemCmd" arbitrary command execution feature to allow remote administrative telnet connectivity from all addresses. New vulnerabilities ------------------- 1. Reflected Cross-Site Scripting (CWE-79), CVE-2014-1225 There is a Cross-Site Scripting vulnerability on the router error page: http://192.168.1.1/error_page.htm?flag=%27%2balert(%27XSS%27)%2b%27 The error page is accessible without authentication. This vulnerability enables the attacker to bypass same-origin policy restrictions enforced by XMLHttpRequest. 2. Authentication bypass (CWE-592) The router error page http://192.168.1.1/error_page.htm includes the current administrative password in clear text. For example if the administrative password is "Joshua", the page includes the following dynamically generated JavaScript: if('1' == '0' || 'Joshua' == 'admin') The error page is accessible without authentication. This vulnerability enables the attacker with same-origin rights, obtained by utilizing the vulnerability above, to read the password by utilizing an XMLHttpRequest call. The script can then perform actions as administrator by utilizing further XMLHttpRequest calls. Vulnerable devices ------------------ The vulnerabilities were discovered from an ASUS RT-N16 device, firmware version 3.0.0.4.374_979. By sampling a small set of ASUS firmware images the following models were also found likely to be vulnerable: ASUS RT-N10U, firmware 3.0.0.4.374_168 ASUS RT-N56U, firmware 3.0.0.4.374_979 ASUS DSL-N55U, firmware 3.0.0.4.374_1397 * ASUS RT-AC66U, firmware 3.0.0.4.374_2050 * ASUS RT-N15U, firmware 3.0.0.4.374_16 ASUS RT-N53, firmware 3.0.0.4.374_311 *) ASUS DSL-N55U and ASUS RT-AC66U did not appear vulnerable to the authentication bypass issue. These devices are still vulnerable to the XSS and if the default password 'admin' has not been changed, they are easily exploitable as well. This list is by no means comprehensive. It is likely that other devices are vulnerable as well. Vendor recommendations ---------------------- 1. Fix the Cross-Site Scripting vulnerabilities, at least from the unauthenticated part of the web interface (error_page.htm) 2. Fix the admin password disclosure on error_page.htm 3. Fix the CSRF (CVE-2013-3093) issue by utilizing anti-CSRF protection End user mitigation ------------------- 1. Install the latest firmware update, version 3.0.0.4.374.4422 or later. or 2. If no firmware update has been released, the end users can partially mitigate the vulnerabilities by changing the "Router Login Name" via the "Administration - System" menu to be something other than "admin". Changing the router default network to something else than 192.168.1.0/24 might also grant some limited protection. Proof-of-concept ---------------- https://sintonen.fi/advisories/asuspwn/ Credits ------- The vulnerabilities were discovered by Harry Sintonen / nSense Oy. Previous work ------------- The Cross-Site Request Forgery and command execution vulnerabilities (CVE-2013-3093) were discovered by Jacob Holcomb / Independent Security Evaluators. The authentication bypass (along with multiple sensitive information disclosure) issue was independently discovered as CVE-2013-5947, yet to be publically disclosured.
idSSV:89392
last seen2017-11-19
modified2015-09-10
published2015-09-10
reporterflsf
titleASUS RT-N16 - Text-plain Admin Password Disclosure