SID 1:3820

Rule Category

FILE-IDENTIFY -- Snort has detecte File Type indicators associated with packet data, which it will use to facilitate a flowbit, a method of stringing rules together. In a flowbit, one rule examines packets for file type indications, which it uses to switch rules pertaining to that file type from a dormant to active state in order to process the appropriate packets. File-type rules stay dormant to prevent alerts on innocent traffic. That same traffic, when contained in, for instance, a .doc file attached to an email, might be a threat and should be scanned.

Alert Message

FILE-IDENTIFY Microsoft Windows CHM file magic detected

Rule Explanation

Integer overflow in Microsoft Windows 98, 2000, XP SP2 and earlier, and Server 2003 SP1 and earlier allows remote attackers to execute arbitrary code via a crafted compiled Help (.CHM) file with a large size field that triggers a heap-based buffer overflow, as demonstrated using a "ms-its:" URL in Internet Explorer. Impact: CVSS base score 10.0 CVSS impact score 10.0 CVSS exploitability score 10.0 confidentialityImpact COMPLETE integrityImpact COMPLETE availabilityImpact COMPLETE Details: Ease of Attack:

What To Look For

No information provided

Known Usage

No public information

False Positives

No known false positives

Contributors

Talos research team. This document was generated from data supplied by the national vulnerability database, a product of the national institute of standards and technology. For more information see [nvd].