FKIE_CVE-2021-43557

Vulnerability from fkie_nvd - Published: 2021-11-22 09:15 - Updated: 2026-06-17 04:11
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
The uri-block plugin in Apache APISIX before 2.10.2 uses $request_uri without verification. The $request_uri is the full original request URI without normalization. This makes it possible to construct a URI to bypass the block list on some occasions. For instance, when the block list contains "^/internal/", a URI like `//internal/` can be used to bypass it. Some other plugins also have the same issue. And it may affect the developer's custom plugin.
References
security@apache.orghttp://www.openwall.com/lists/oss-security/2021/11/22/1Mailing List, Third Party Advisory
security@apache.orghttp://www.openwall.com/lists/oss-security/2021/11/22/2Mailing List, Third Party Advisory
security@apache.orghttp://www.openwall.com/lists/oss-security/2021/11/23/1Exploit, Mailing List, Third Party Advisory
security@apache.orghttps://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7hExploit, Mailing List, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/11/22/1Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/11/22/2Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://www.openwall.com/lists/oss-security/2021/11/23/1Exploit, Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7hExploit, Mailing List, Vendor Advisory
Impacted products
Vendor Product Version
apache apisix *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Apache APISIX",
          "vendor": "Apache Software Foundation",
          "versions": [
            {
              "lessThan": "Apache APISIX 1.5*",
              "status": "affected",
              "version": "1.5",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "security@apache.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:apache:apisix:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E6E300E2-7036-4813-B7A7-48F922753C76",
              "versionEndExcluding": "2.10.2",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The uri-block plugin in Apache APISIX before 2.10.2 uses $request_uri without verification. The $request_uri is the full original request URI without normalization. This makes it possible to construct a URI to bypass the block list on some occasions. For instance, when the block list contains \"^/internal/\", a URI like `//internal/` can be used to bypass it. Some other plugins also have the same issue. And it may affect the developer\u0027s custom plugin."
    },
    {
      "lang": "es",
      "value": "El plugin uri-block en Apache APISIX versiones anteriores a 2.10.2, usa $request_uri sin verificaci\u00f3n. La $request_uri es la URI original completa de la petici\u00f3n sin normalizar. Esto hace posible construir un URI para evitar la lista de bloqueo en algunas ocasiones. Por ejemplo, cuando la lista de bloqueo contiene \"^/internal/\", puede usarse una URI como \"//internal/\" para omitirla. Algunos otros plugins tambi\u00e9n presentan el mismo problema. Y puede afectar al plugin personalizado del desarrollador"
    }
  ],
  "id": "CVE-2021-43557",
  "lastModified": "2026-06-17T04:11:07.910",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "NONE",
          "baseScore": 5.0,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "NONE",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:N/A:N",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 2.9,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2021-11-22T09:15:07.627",
  "references": [
    {
      "source": "security@apache.org",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/11/22/1"
    },
    {
      "source": "security@apache.org",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/11/22/2"
    },
    {
      "source": "security@apache.org",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/11/23/1"
    },
    {
      "source": "security@apache.org",
      "tags": [
        "Exploit",
        "Mailing List",
        "Vendor Advisory"
      ],
      "url": "https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7h"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/11/22/1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/11/22/2"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "url": "http://www.openwall.com/lists/oss-security/2021/11/23/1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Exploit",
        "Mailing List",
        "Vendor Advisory"
      ],
      "url": "https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7h"
    }
  ],
  "sourceIdentifier": "security@apache.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-77"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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