一、信息收集
1.端口扫描
使用nmap进行端口扫描,发现其开放了22、80、8080、9000端口。
访问其8080端口,发现是一个web界面。
浏览页面内容,提升有一些提示。
提示存在一个py脚本,访问看看。
发现提示是404
2.目录爆破
使用gobuster进行目录爆破。
gobuster dir -u http://10.10.10.168:8080 -w /usr/share/wordlists/dirbuster/directory-list-2.3-small.txt ,发现都是404.
3.使用wfuzz进行fuzz
由于我们不知道文件存放在那个具体路径下,所以将使用wfuzzurl 来定位http://10.10.10.168:8080/FUZZ/SuperSecureServer.py其路径。
wfuzz -c-w /usr/share/dirbuster/wordlists/directory-list-2.3-small.txt -u http://10.10.10.168:8080/FUZZ/SuperSecureServer.py --hl 6 --hw 367
发现它在/developer目录之下。
访问看看。成功看到脚本内容。
4.代码分析
将源码copy出来,然后进行分析。
import socket import threading from datetime import datetime import sys import os import mimetypes import urllib.parse import subprocess respTemplate = """HTTP/1.1 {statusNum} {statusCode} Date: {dateSent} Server: {server} Last-Modified: {modified} Content-Length: {length} Content-Type: {contentType} Connection: {connectionType} {body} """ DOC_ROOT = "DocRoot" CODES = {"200": "OK", "304": "NOT MODIFIED", "400": "BAD REQUEST", "401": "UNAUTHORIZED", "403": "FORBIDDEN", "404": "NOT FOUND", "500": "INTERNAL SERVER ERROR"} MIMES = {"txt": "text/plain", "css":"text/css", "html":"text/html", "png": "image/png", "jpg":"image/jpg", "ttf":"application/octet-stream","otf":"application/octet-stream", "woff":"font/woff", "woff2": "font/woff2", "js":"application/javascript","gz":"application/zip", "py":"text/plain", "map": "application/octet-stream"} class Response: def __init__(self, **kwargs): self.__dict__.update(kwargs) now = datetime.now() self.dateSent = self.modified = now.strftime("%a, %d %b %Y %H:%M:%S") def stringResponse(self): return respTemplate.format(**self.__dict__) class Request: def __init__(self, request): self.good = True try: request = self.parseRequest(request) self.method = request["method"] self.doc = request["doc"] self.vers = request["vers"] self.header = request["header"] self.body = request["body"] except: self.good = False def parseRequest(self, request): req = request.strip("\r").split("\n") method,doc,vers = req[0].split(" ") header = req[1:-3] body = req[-1] headerDict = {} for param in header: pos = param.find(": ") key, val = param[:pos], param[pos+2:] headerDict.update({key: val}) return {"method": method, "doc": doc, "vers": vers, "header": headerDict, "body": body} class Server: def __init__(self, host, port): self.host = host self.port = port self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) self.sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.sock.bind((self.host, self.port)) def listen(self): self.sock.listen(5) while True: client, address = self.sock.accept() client.settimeout(60) threading.Thread(target = self.listenToClient,args = (client,address)).start() def listenToClient(self, client, address): size = 1024 while True: try: data = client.recv(size) if data: # Set the response to echo back the received data req = Request(data.decode()) self.handleRequest(req, client, address) client.shutdown() client.close() else: raise error('Client disconnected') except: client.close() return False def handleRequest(self, request, conn, address): if request.good: # try: # print(str(request.method) + " " + str(request.doc), end=' ') # print("from {0}".format(address[0])) # except Exception as e: # print(e) document = self.serveDoc(request.doc, DOC_ROOT) statusNum=document["status"] else: document = self.serveDoc("/errors/400.html", DOC_ROOT) statusNum="400" body = document["body"] statusCode=CODES[statusNum] dateSent = "" server = "BadHTTPServer" modified = "" length = len(body) contentType = document["mime"] # Try and identify MIME type from string connectionType = "Closed" resp = Response( statusNum=statusNum, statusCode=statusCode, dateSent = dateSent, server = server, modified = modified, length = length, contentType = contentType, connectionType = connectionType, body = body ) data = resp.stringResponse() if not data: return -1 conn.send(data.encode()) return 0 def serveDoc(self, path, docRoot): path = urllib.parse.unquote(path) try: info = "output = 'Document: {}'" # Keep the output for later debug exec(info.format(path)) # This is how you do string formatting, right? cwd = os.path.dirname(os.path.realpath(__file__)) docRoot = os.path.join(cwd, docRoot) if path == "/": path = "/index.html" requested = os.path.join(docRoot, path[1:]) if os.path.isfile(requested): mime = mimetypes.guess_type(requested) mime = (mime if mime[0] != None else "text/html") mime = MIMES[requested.split(".")[-1]] try: with open(requested, "r") as f: data = f.read() except: with open(requested, "rb") as f: data = f.read() status = "200" else: errorPage = os.path.join(docRoot, "errors", "404.html") mime = "text/html" with open(errorPage, "r") as f: data = f.read().format(path) status = "404" except Exception as e: print(e) errorPage = os.path.join(docRoot, "errors", "500.html") mime = "text/html" with open(errorPage, "r") as f: data = f.read() status = "500" return {"body": data, "mime": mime, "status": status}
在翻译源码过程中,第一眼就看到了注释的地方。就想到了exec函数。
根据 This is how you do string formatting, right?,的意思:不,这不是您进行字符串格式化的方式。path将用户输入 ( )传递给exec总是很危险的。我开始翻阅代码,看看是否可以控制path它何时进入serveDoc.
def handleRequest(self, request, conn, address): if request.good: document = self.serveDoc(request.doc, DOC_ROOT) statusNum=document["status"] else: document = self.serveDoc("/errors/400.html", DOC_ROOT) statusNum="400" body = document["body"]
还有这句注释:Set the response to echo back the received data,然后开始读源码。如果这request.good为真,我会失去控制,path被硬编码为"/errors/400.html".
handleRequest从以下位置调用listenToClient:
def listenToClient(self, client, address): size = 1024 while True: try: data = client.recv(size) if data: # Set the response to echo back the received data req = Request(data.decode()) self.handleRequest(req, client, address) client.shutdown() client.close() else: raise error('Client disconnected') except: client.close() return False
这是一个循环,它接收数据,处理成一个Request对象,然后调用handleRequest ,条件就是该Request对象.good是真,并且.doc是我的测试代码。
该类Request将数据转换为对象__init__:
class Request: def __init__(self, request): self.good = True try: request = self.parseRequest(request) self.method = request["method"] self.doc = request["doc"] self.vers = request["vers"] self.header = request["header"] self.body = request["body"] except: self.good = False def parseRequest(self, request): req = request.strip("\r").split("\n") method,doc,vers = req[0].split(" ") header = req[1:-3] body = req[-1] headerDict = {} for param in header: pos = param.find(": ") key, val = param[:pos], param[pos+2:] headerDict.update({key: val}) return {"method": method, "doc": doc, "vers": vers, "header": headerDict, "body": body}
只要数据具有带有 url、版本、标题和正文等正常格式,它就会返回self.good = True. 而且,这doc就是 url 字符串中的内容,是可控的。










