CVE-2006-0459

Estado: ModificadaAlta (7.5)—

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.

CVSS

Versión: 2.0
Vector: AV:N/AC:L/Au:N/C:P/I:P/A:P
Puntuación base: 7.5

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 4.77%
Percentil entre todas las CVEs puntuadas: 92
Fecha de la puntuación: 3/10/2026

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

Westes — Flex

CWE

CWE-119

Referencias

JSON original (NVD)

Mostrar

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  "id": "CVE-2006-0459",
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      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
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          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "HIGH",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": true,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
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      "affectedData": [
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  "published": "2006-03-29T23:02:00.000",
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        {
          "lang": "en",
          "value": "CWE-119"
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  "descriptions": [
    {
      "lang": "en",
      "value": "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."
    }
  ],
  "lastModified": "2026-06-16T22:20:38.970",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:westes:flex:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E0145625-8490-4671-A17C-85426C258AF9",
              "versionEndIncluding": "2.5.32"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "vendorComments": [
    {
      "comment": "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.\n",
      "lastModified": "2006-08-16T00:00:00",
      "organization": "Red Hat"
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}