CVE-2006-0459

Summary

CVECVE-2006-0459
StatePUBLISHED
Assignerredhat
Source PriorityCVE Program / NVD first with legacy fallback
Published2006-03-29 23:02:00 UTC
Updated2025-04-03 01:03:51 UTC
Descriptionflex.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.

Risk And Classification

Primary CVSS: v2.0 7.5 from [email protected]

AV:N/AC:L/Au:N/C:P/I:P/A:P

EPSS: 0.039700000 probability, percentile 0.883960000 (date 2026-04-19)

Problem Types: CWE-119 | n/a

CVSS v2.0 Breakdown

Access Vector
Network
Access Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial

AV:N/AC:L/Au:N/C:P/I:P/A:P

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Westes Flex All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Na N/a affected n/a Not specified

References

ReferenceSourceLinkTags
USN-260-1: flex vulnerability | Ubuntu security notices af854a3a-2127-422b-91ae-364da2661108 usn.ubuntu.com Third Party Advisory
Gentoo update for flex - Advisories - Secunia af854a3a-2127-422b-91ae-364da2661108 secunia.com Vendor Advisory
www.us.debian.org/security/2006/dsa-1020 af854a3a-2127-422b-91ae-364da2661108 www.us.debian.org Patch, Vendor Advisory
SecurityReason af854a3a-2127-422b-91ae-364da2661108 securityreason.com Third Party Advisory
IBM X-Force Exchange af854a3a-2127-422b-91ae-364da2661108 exchange.xforce.ibmcloud.com VDB Entry
Gentoo Linux Documentation -- flex: Potential insecure code generation af854a3a-2127-422b-91ae-364da2661108 www.gentoo.org Third Party Advisory
www.osvdb.org/23440 af854a3a-2127-422b-91ae-364da2661108 www.osvdb.org Broken Link, Patch
Flex Code Generation Buffer Overflow Vulnerability af854a3a-2127-422b-91ae-364da2661108 www.securityfocus.com Patch, Third Party Advisory, VDB Entry
flex: the fast lexical analyser - Browse Files at SourceForge.net af854a3a-2127-422b-91ae-364da2661108 prdownloads.sourceforge.net Product
Ubuntu update for flex / gpc - Advisories - Secunia af854a3a-2127-422b-91ae-364da2661108 secunia.com Vendor Advisory
Webmail - OVH af854a3a-2127-422b-91ae-364da2661108 www.vupen.com Broken Link, URL Repurposed
flex: the fast lexical analyser / Thread: [Flex-announce] flex 2.5.33 released af854a3a-2127-422b-91ae-364da2661108 sourceforge.net Release Notes
Secunia - Advisories - Flex Generated C Parsers Buffer Overflow Vulnerability af854a3a-2127-422b-91ae-364da2661108 secunia.com Patch, Vendor Advisory
Secunia - Advisories - Debian update for flex af854a3a-2127-422b-91ae-364da2661108 secunia.com Patch, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

OrganizationPublishedContributorStatement
Red Hat2006-08-16Mark J CoxThis 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.
© CVE.report 2026 |

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report