Vulnerability from bitnami_vulndb
Published
2025-08-11 13:53
Modified
2025-08-11 14:19
Summary
UAF due to php_filter_float() failing
Details

In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "libphp",
        "purl": "pkg:bitnami/libphp"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "7.4.0"
            },
            {
              "fixed": "7.4.28"
            },
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.0.16"
            },
            {
              "introduced": "8.1.0"
            },
            {
              "fixed": "8.1.3"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-21708"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:php:php:*:*:*:*:*:*:*:*"
    ],
    "severity": "Critical"
  },
  "details": "In PHP versions 7.4.x below 7.4.28, 8.0.x below 8.0.16, and 8.1.x below 8.1.3, when using filter functions with FILTER_VALIDATE_FLOAT filter and min/max limits, if the filter fails, there is a possibility to trigger use of allocated memory after free, which can result it crashes, and potentially in overwrite of other memory chunks and RCE. This issue affects: code that uses FILTER_VALIDATE_FLOAT with min/max limits.",
  "id": "BIT-libphp-2021-21708",
  "modified": "2025-08-11T14:19:40.295Z",
  "published": "2025-08-11T13:53:33.524Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://bugs.php.net/bug.php?id=81708"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-21708"
    },
    {
      "type": "WEB",
      "url": "https://security.gentoo.org/glsa/202209-20"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20220325-0004/"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "UAF due to php_filter_float() failing"
}


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Detection rules are retrieved from Rulezet.