National Vulnerability Database

National Vulnerability Database

National Vulnerability

CVE-2006-0459 Detail

Current Description

flex.skl in Will Estes and John Millaway Fast Lexical Analyzer Generator (flex) before 2.5.33 does not allocate enough memory for grammars containing (1) REJECT statements or (2) trailing context rules, which causes flex to generate code that contains a buffer overflow that might allow context-dependent attackers to execute arbitrary code.

Source:  MITRE      Last Modified:  03/29/2006      View Analysis Description

Quick Info

CVE Dictionary Entry:
Original release date:
Last revised:


CVSS Severity (version 2.0):
CVSS v2 Base Score:
7.5 HIGH
(AV:N/AC:L/Au:N/C:P/I:P/A:P) (legend)
Impact Subscore:
Exploitability Subscore:
CVSS Version 2 Metrics:
Access Vector:
Network exploitable
Access Complexity:
Not required to exploit
Impact Type:
Provides user account access, Allows partial confidentiality, integrity, and availability violation; Allows unauthorized disclosure of information; Allows disruption of service

Vendor Statements (disclaimer)

Official Statement from Red Hat (08/16/2006)

This issue only affects parsers which are generated by grammars which either use REJECT or rules with a variable trailing context (in these rules the parser has to keep all backtracking paths). The Red Hat Security Response Team analysed all packages that include flex generated parsers in Red Hat Enterprise Linux (2.1, 3, and 4) and found none were vulnerable.

References to Advisories, Solutions, and Tools

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Hyperlink Resource Type Source Name External Source CONFIRM External Source SREASON 570 External Source MLIST [flex-announce] 20060222 flex 2.5.33 released External Source GENTOO GLSA-200603-07 Patch External Source BID 16896 External Source UBUNTU USN-260-1 Patch; Vendor Advisory External Source DEBIAN DSA-1020 External Source VUPEN ADV-2006-0770 External Source XF flex-bypass-security(24995)

Technical Details

Vulnerability Type (View All)

Change History 3 change records found - show changes