{
    "id": "CVE-2021-40438",
    "published": "2021-09-16 15:15:07",
    "last_modified": "2026-08-06 05:16:35",
    "cvss_score": "9.0",
    "cvss_severity": "CRITICAL",
    "cvss_version": "3.1",
    "cvss_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
    "cwe": "CWE-918",
    "description": "A crafted request uri-path can cause mod_proxy to forward the request to an origin server choosen by the remote user. This issue affects Apache HTTP Server 2.4.48 and earlier.",
    "epss_score": "0.99999",
    "epss_percentile": "0.99997",
    "kev": 1,
    "kev_due": "2021-12-15",
    "has_exploit": 0,
    "updated_at": "2026-09-26 18:28:08",
    "priority": {
        "rank": 1,
        "label": "Patch first",
        "why": "On CISA KEV — known exploited in the wild, due 2021-12-15."
    },
    "products": [
        {
            "vendor": "apache",
            "product": "http_server"
        },
        {
            "vendor": "broadcom",
            "product": "brocade_fabric_operating_system_firmware"
        },
        {
            "vendor": "debian",
            "product": "debian_linux"
        },
        {
            "vendor": "f5",
            "product": "f5os"
        },
        {
            "vendor": "fedoraproject",
            "product": "fedora"
        },
        {
            "vendor": "netapp",
            "product": "cloud_backup"
        },
        {
            "vendor": "netapp",
            "product": "clustered_data_ontap"
        },
        {
            "vendor": "netapp",
            "product": "storagegrid"
        },
        {
            "vendor": "oracle",
            "product": "enterprise_manager_ops_center"
        },
        {
            "vendor": "oracle",
            "product": "http_server"
        },
        {
            "vendor": "oracle",
            "product": "instantis_enterprisetrack"
        },
        {
            "vendor": "oracle",
            "product": "secure_global_desktop"
        },
        {
            "vendor": "oracle",
            "product": "zfs_storage_appliance_kit"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_eus"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_arm_64"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_arm_64_eus"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_ibm_z_systems"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_ibm_z_systems_eus"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_ibm_z_systems_eus_s390x"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_power_big_endian"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_power_little_endian"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_power_little_endian_eus"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_for_scientific_computing"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_server"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_server_aus"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_server_for_power_little_endian_update_services_for_sap_solutions"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_server_tus"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_server_update_services_for_sap_solutions"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_server_workstation"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_update_services_for_sap_solutions"
        },
        {
            "vendor": "redhat",
            "product": "enterprise_linux_workstation"
        },
        {
            "vendor": "redhat",
            "product": "jboss_core_services"
        },
        {
            "vendor": "redhat",
            "product": "software_collections"
        },
        {
            "vendor": "resf",
            "product": "rocky_linux"
        },
        {
            "vendor": "siemens",
            "product": "ruggedcom_nms"
        },
        {
            "vendor": "siemens",
            "product": "sinec_nms"
        },
        {
            "vendor": "siemens",
            "product": "sinema_remote_connect_server"
        },
        {
            "vendor": "siemens",
            "product": "sinema_server"
        },
        {
            "vendor": "tenable",
            "product": "tenable.sc"
        }
    ],
    "kev_detail": {
        "cve_id": "CVE-2021-40438",
        "date_added": "2021-12-01",
        "due_date": "2021-12-15",
        "vendor": "Apache",
        "product": "Apache",
        "name": "Apache HTTP Server-Side Request Forgery (SSRF)",
        "ransomware": 1
    },
    "exploits": [],
    "refs_list": [
        "https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdf",
        "https://httpd.apache.org/security/vulnerabilities_24.html",
        "https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r82838efc5fa6fc4c73986399c9b71573589f78b31846aff5bd9b1697%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r82c077663f9759c7df5a6656f925b3ee4f55fcd33c889ba7cd687029%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/rf6954e60b1c8e480678ce3d02f61b8a788997785652e9557a3265c00%40%3Cusers.httpd.apache.org%3E",
        "https://lists.debian.org/debian-lts-announce/2021/10/msg00001.html",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SPBR6WUYBJNACHKE65SPL7TJOHX7RHWD/",
        "https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZNCYSR3BXT36FFF4XTCPL3HDQK4VP45R/",
        "https://security.gentoo.org/glsa/202208-20",
        "https://security.netapp.com/advisory/ntap-20211008-0004/",
        "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apache-httpd-2.4.49-VWL69sWQ",
        "https://www.debian.org/security/2021/dsa-4982",
        "https://www.oracle.com/security-alerts/cpuapr2022.html",
        "https://www.oracle.com/security-alerts/cpujan2022.html",
        "https://www.tenable.com/security/tns-2021-17",
        "https://cert-portal.siemens.com/productcert/pdf/ssa-685781.pdf",
        "https://httpd.apache.org/security/vulnerabilities_24.html",
        "https://lists.apache.org/thread.html/r210807d0bb55f4aa6fbe1512be6bcc4dacd64e84940429fba329967a%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r2eb200ac1340f69aa22af61ab34780c531d110437910cb9c0ece3b37%40%3Cbugs.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r3925e167d5eb1c75def3750c155d753064e1d34a143028bb32910432%40%3Cusers.httpd.apache.org%3E",
        "https://lists.apache.org/thread.html/r61fdbfc26ab170f4e6492ef3bd5197c20b862ce156e9d5a54d4b899c%40%3Cusers.httpd.apache.org%3E"
    ]
}