CVE-2005-1935: Microsoft Windows 2000

High severity, CVSS 7.5. EPSS: 26.6% chance of exploitation in the next 30 days.

Heap-based buffer overflow in the BERDecBitString function in Microsoft ASN.1 library (MSASN1.DLL) allows remote attackers to execute arbitrary code via nested constructed bit strings, which leads to a realloc of a non-null pointer and causes the function to overwrite previously freed memory, as demonstrated using a SPNEGO token with a constructed bit string during HTTP authentication, and a different vulnerability than CVE-2003-0818. NOTE: the researcher has claimed that MS:MS04-007 fixes this issue.

Affected products

• Microsoft Windows 2000: any version
• Microsoft Windows 2003 Server: version 64-bit only; version r2 only
• Microsoft Windows Nt: version 4.0 only
• Microsoft Windows XP: any version

Published 2005-06-13. Last modified 2026-06-16.