cbcvebase.
CVE-2002-1123
published 2002-09-24

CVE-2002-1123: Buffer overflow in the authentication function for Microsoft SQL Server 2000 and Microsoft Desktop Engine (MSDE) 2000 allows remote attackers to execute…

PriorityP259high7.5CVSS 2.0
AVNACLAuNCPIPAP
EXPLOIT
EPSS
77.71%
99.5th percentile
Buffer overflow in the authentication function for Microsoft SQL Server 2000 and Microsoft Desktop Engine (MSDE) 2000 allows remote attackers to execute arbitrary code via a long request to TCP port 1433, aka the "Hello" overflow.

Affected

2 ranges
VendorProductVersion rangeFixed in
microsoftdata_engine
microsoftsql_server

Detection & IOCsextracted from sources · hover to see the quote

portTCP/1433
bytes
\x12\x01\x00\x34\x00\x00\x00\x00\x00\x00\x15\x00\x06\x01\x00\x1b\x00\x01\x02\x00\x1c\x00\x0c\x03\x00\x28\x00\x04\xff\x08\x00\x02\x10\x00\x00\x00
bytes
\x00\x24\x01\x00\x00
bytes
\x1B\xA5\xEE\x34
  • Detect exploit attempts by matching the malformed MSSQL 'Hello' packet header bytes (0x12 0x01 0x00 0x34 ...) followed by an oversized payload (>=528 bytes of filler) and the tail bytes (0x00 0x24 0x01 0x00 0x00) on TCP/1433.
  • Alert on TCP/1433 connections where the initial client packet begins with the 36-byte MSSQL pre-auth 'Hello' header (starting \x12\x01\x00\x34) and the total packet length significantly exceeds 36 bytes, indicating a buffer overflow attempt before authentication.
  • If the SQL Server process stops responding (no reply) after receiving a large packet on TCP/1433, this is a strong indicator of successful exploitation or crash — the PoC checks for absence of response as the vulnerability indicator.
  • The Metasploit module targets MSSQL 2000 / MSDE installations prior to SP3; use mssql_ping or banner-grabbing on TCP/1433 to identify unpatched instances as high-priority targets.
  • ·The exploit payload space is limited to 512 bytes and null bytes (\x00) are bad characters; shellcode used in detection rules or emulation must respect these constraints.
  • ·The Metasploit module uses two hardcoded return addresses (0x42b68aba and 0x42d01e50) specific to MSSQL 2000 / MSDE targets; detection signatures relying on these exact values may miss variants using different return addresses.
  • ·Additional MSSQL instances may be discoverable on non-standard ports via the UDP/1434 resolver service; scanning only TCP/1433 may miss all exposed instances.
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