{
    "CVE_data_meta": {
        "ASSIGNER": "security@apache.org",
        "ID": "CVE-2021-43557",
        "STATE": "PUBLIC",
        "TITLE": "Path traversal in request_uri variable"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Apache APISIX",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": ">=",
                                            "version_name": "Apache APISIX 1.5",
                                            "version_value": "1.5"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "Apache Software Foundation"
                }
            ]
        }
    },
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "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's custom plugin."
            }
        ]
    },
    "generator": {
        "engine": "Vulnogram 0.0.9"
    },
    "impact": [
        {
            "other": "moderate"
        }
    ],
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "Use Nginx's $request_uri variable without verification"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "refsource": "MISC",
                "url": "https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7h",
                "name": "https://lists.apache.org/thread/18jyd458ptocr31rnkjs71w4h366mv7h"
            },
            {
                "refsource": "MLIST",
                "name": "[oss-security] 20211122 CVE-2021-43557: Apache APISIX: Path traversal in request_uri variable",
                "url": "http://www.openwall.com/lists/oss-security/2021/11/22/1"
            },
            {
                "refsource": "MLIST",
                "name": "[oss-security] 20211122 Re: CVE-2021-43557: Apache APISIX: Path traversal in request_uri variable",
                "url": "http://www.openwall.com/lists/oss-security/2021/11/22/2"
            },
            {
                "refsource": "MLIST",
                "name": "[oss-security] 20211123 Re: CVE-2021-43557: Apache APISIX: Path traversal in request_uri variable",
                "url": "http://www.openwall.com/lists/oss-security/2021/11/23/1"
            }
        ]
    },
    "source": {
        "discovery": "UNKNOWN"
    },
    "work_around": [
        {
            "lang": "eng",
            "value": "1. Upgrade to APISIX 2.10.2, or apply this commit which provides a normalized $request_uri: https://github.com/apache/apisix/commit/9fc38330e82ce46e2aaabceef7d61708c91782db\n2. Carefully review custom code, find & fix the usage of $request_uri without verification."
        }
    ]
}