{
    "CVE_data_meta": {
        "ASSIGNER": "security@apache.org",
        "ID": "CVE-2021-31618",
        "STATE": "PUBLIC",
        "TITLE": "NULL pointer dereference on specially crafted HTTP/2 request"
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Apache HTTP Server",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "=",
                                            "version_value": "2.4.47"
                                        }
                                    ]
                                }
                            }
                        ]
                    },
                    "vendor_name": "Apache Software Foundation"
                }
            ]
        }
    },
    "credit": [
        {
            "lang": "eng",
            "value": "Apache HTTP server would like to thank  LI ZHI XIN from NSFocus for reporting this."
        }
    ],
    "data_format": "MITRE",
    "data_type": "CVE",
    "data_version": "4.0",
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of these restrictions and HTTP response is sent to the client with a status code indicating why the request was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the offending header was the very first one received or appeared in a a footer. This led to a NULL pointer dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2 request is easy to craft and submit, this can be exploited to DoS the server. This issue affected mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never released."
            }
        ]
    },
    "generator": {
        "engine": "Vulnogram 0.0.9"
    },
    "impact": [
        {
            "other": "important"
        }
    ],
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "CWE-476 NULL Pointer Dereference"
                    }
                ]
            }
        ]
    },
    "references": {
        "reference_data": [
            {
                "refsource": "MISC",
                "url": "http://httpd.apache.org/security/vulnerabilities_24.html",
                "name": "http://httpd.apache.org/security/vulnerabilities_24.html"
            },
            {
                "refsource": "MLIST",
                "name": "[oss-security] 20210609 CVE-2021-31618: Apache httpd: NULL pointer dereference on specially crafted HTTP/2 request",
                "url": "http://www.openwall.com/lists/oss-security/2021/06/10/9"
            },
            {
                "refsource": "MISC",
                "url": "https://seclists.org/oss-sec/2021/q2/206",
                "name": "https://seclists.org/oss-sec/2021/q2/206"
            },
            {
                "refsource": "MLIST",
                "name": "[httpd-cvs] 20210615 svn commit: r1890801 - /httpd/site/trunk/content/security/json/CVE-2021-31618.json",
                "url": "https://lists.apache.org/thread.html/r14b66ef0f4f569fd515a3f96cd4eb58bd9a8ff525cc326bb0359664f@%3Ccvs.httpd.apache.org%3E"
            },
            {
                "refsource": "MLIST",
                "name": "[httpd-cvs] 20210615 svn commit: r1075782 - in /websites/staging/httpd/trunk/content: ./ security/json/CVE-2021-31618.json security/vulnerabilities_24.html",
                "url": "https://lists.apache.org/thread.html/r783b6558abf3305b17ea462bed4bd66d82866438999bf38cef6d11d1@%3Ccvs.httpd.apache.org%3E"
            },
            {
                "refsource": "FEDORA",
                "name": "FEDORA-2021-051639aad4",
                "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2NKJ3ZA3FTSZ2QBBPKS6BYGAWYRABNQQ/"
            },
            {
                "refsource": "FEDORA",
                "name": "FEDORA-2021-181f29c392",
                "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/A73QJ4HPUMU26I6EULG6SCK67TUEXZYR/"
            },
            {
                "refsource": "MLIST",
                "name": "[debian-lts-announce] 20210709 [SECURITY] [DLA 2706-1] apache2 security update",
                "url": "https://lists.debian.org/debian-lts-announce/2021/07/msg00006.html"
            },
            {
                "refsource": "DEBIAN",
                "name": "DSA-4937",
                "url": "https://www.debian.org/security/2021/dsa-4937"
            },
            {
                "refsource": "GENTOO",
                "name": "GLSA-202107-38",
                "url": "https://security.gentoo.org/glsa/202107-38"
            },
            {
                "url": "https://www.oracle.com/security-alerts/cpuoct2021.html",
                "refsource": "MISC",
                "name": "https://www.oracle.com/security-alerts/cpuoct2021.html"
            },
            {
                "refsource": "CONFIRM",
                "name": "https://security.netapp.com/advisory/ntap-20210727-0008/",
                "url": "https://security.netapp.com/advisory/ntap-20210727-0008/"
            },
            {
                "refsource": "MLIST",
                "name": "[oss-security] 20240313 Re: CVE-2021-31618: Apache httpd: NULL pointer dereference on specially crafted HTTP/2 request",
                "url": "http://www.openwall.com/lists/oss-security/2024/03/13/2"
            }
        ]
    },
    "source": {
        "discovery": "UNKNOWN"
    },
    "work_around": [
        {
            "lang": "eng",
            "value": "On unpatched servers, the `h2` protocol can be disabled by removing it from the `Protocols` configuration. If the `h2` protocol is not enabled, the server is not affected by this vulnerability."
        }
    ]
}