Flex lexicographical scanner class buffer overflow
| flex-lexicographical-scanner-bo (24995) |  High Risk |
Description:
Fast Lexical Analyzer (Flex) is vulnerable to a buffer overflow in a particular class of lexicographical scanners. A remote attacker could exploit this vulnerability to execute arbitrary commands on the system.
*CVSS:
| Base Score: | 7 |
| Access Vector: | Remote |
| Access Complexity: | Low |
| Authentication: | Not Required |
| Confidentiality Impact: | Partial |
| Integrity Impact: | Partial |
| Availability Impact: | Partial |
| Temporal Score: | 5.2 |
| Exploitability: | Unproven |
| Remediation Level: | Official-Fix |
| Report Confidence: | Confirmed |
Consequences:
Gain Access
Remedy:
Upgrade to the latest version of Flex (2.5.33 or later), available from the Flex Web site. See References.
For Debian GNU/Linux:
Refer to DSA-1020-1 for patch, upgrade, or suggested workaround information. See References.
For Gentoo Linux:
Refer to Gentoo Linux Security Announcement GLSA 2006-03-07 for patch, upgrade, or suggested workaround information. See References.
For Ubuntu Linux:
Refer to USN-260-1 for patch, upgrade, or suggested workaround information. See References.
For other distributions:
Contact your vendor for patch or upgrade information.
References:
- Flex Web site: flex: The Fast Lexical Analyzer.
- flex-announce Mailing List, 2006-02-22 18:09: flex 2.5.33 released.
- BID-16896: Flex Code Generation Buffer Overflow Vulnerability
- CVE-2006-0459: 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.
- CVE-2006-0975: ** REJECT ** DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2006-0459. Reason: This candidate is a reservation duplicate of CVE-2006-0459. Notes: All CVE users should reference CVE-2006-0459 instead of this candidate. All references and descriptions in this candidate have been removed to prevent accidental usage.
- DSA-1020: flex -- buffer overflow
- GLSA-200603-07: flex: Potential insecure code generation
- OSVDB ID: 23440: Fast Lexical Analyzer Generator (Flex) Multiple Lexicographical Scanners Overflow
- SA19071: Flex Generated C Parsers Buffer Overflow Vulnerability
- USN-260-1: flex vulnerability
- VUPEN/ADV-2006-0770: Fast Lexical Analyzer (Flex) Scanners Buffer Overflow Vulnerability
Platforms Affected:
- Canonical Ubuntu 4.10
- Canonical Ubuntu 5.04
- Canonical Ubuntu 5.10
- Debian Debian Linux 3.1
- Flex Flex prior to 2.5.33
- Gentoo Linux
Reported:
Mar 01, 2006
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For corrections or additions please email xforce@iss.net
* According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES "AS IS" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.
The information within this database may change without notice. 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. In no event shall IBM be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.