High
Security advisory
A crafted URI sent to httpd configured as a forward proxy (ProxyRequests on) can cause a crash (NULL pointer dereference) or, for configurations mixing forward and reverse proxy declarations, can allow for requests to be directed to a declared Unix Domain Socket endpoint (Server Side Request Forgery). This issue affects Apache HTTP Server 2.4.7 up to 2.4.51 (included).
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2021-44224
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 06:51 UTC · Revision 1
Source evidence
A crafted URI sent to httpd configured as a forward proxy (ProxyRequests on) can cause a crash (NULL pointer dereference) or, for configurations mixing forward and reverse proxy declarations, can allow for requests to be directed to a declared Unix Domain Socket endpoint (Server Side Request Forgery). This issue affects Apache HTTP Server 2.4.7 up to 2.4.51 (included).
osv:CVE-2021-44224
Complete source record
{
"id": "340fd1ff202aea9993658af0b0df0d47b27759654e5ffe9ecb3ed6df1bdc28e0",
"url": "https://osv.dev/vulnerability/CVE-2021-44224",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2021-44224",
"summary": "A crafted URI sent to httpd configured as a forward proxy (ProxyRequests on) can cause a crash (NULL pointer dereference) or, for configurations mixing forward and reverse proxy declarations, can allow for requests to be directed to a declared Unix Domain Socket endpoint (Server Side Request Forgery). This issue affects Apache HTTP Server 2.4.7 up to 2.4.51 (included).",
"evidence": "osv:CVE-2021-44224",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2021-44224",
"aliases": [
"BIT-apache-2021-44224",
"CVE-2021-44224"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/apache/httpd",
"type": "GIT",
"events": [
{
"introduced": "f2b561181dbd0c689fd583c60878ce05854ec5f9"
},
{
"fixed": "fed3b8a079835cd63648d8903bc69243ce2c472a"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2.4.7"
},
{
"fixed": "2.4.52"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-44224.json"
}
}
],
"modified": "2026-10-24T10:30:45.511718183Z",
"provider": "osv",
"references": [
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BFSWOH4X77CV7AH7C4RMHUBDWKQDL4YH/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGWILBORT67SHMSLYSQZG2NMXGCMPUZO/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X73C35MMMZGBVPQQCH7LQZUMYZNQA5FO/",
"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Z7H26WJ6TPKNWV3QKY4BHKUKQVUTZJTD/",
"https://security.gentoo.org/glsa/202208-20",
"https://security.netapp.com/advisory/ntap-20211224-0001/",
"https://support.apple.com/kb/HT213255",
"https://support.apple.com/kb/HT213256",
"https://support.apple.com/kb/HT213257",
"https://www.debian.org/security/2022/dsa-5035",
"https://www.tenable.com/security/tns-2022-01",
"https://www.tenable.com/security/tns-2022-03",
"https://www.oracle.com/security-alerts/cpuapr2022.html",
"https://www.oracle.com/security-alerts/cpujan2022.html"
],
"provider_metadata": {
"unresolved_ranges": [
{
"cpes": [
"cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*"
],
"vendor_product": "apple:macos",
"extracted_events": [
{
"range": [
{
"fixed": "10.15.7"
},
{
"introduced": "11.0"
},
{
"fixed": "11.6.6"
},
{
"introduced": "12.0.0"
},
{
"fixed": "12.4"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:communications_element_manager:*:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_element_manager",
"extracted_events": [
{
"range": [
{
"fixed": "9.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:communications_session_report_manager:*:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_session_report_manager",
"extracted_events": [
{
"range": [
{
"fixed": "9.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:communications_session_route_manager:*:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_session_route_manager",
"extracted_events": [
{
"range": [
{
"fixed": "9.0"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:a:tenable:tenable.sc:*:*:*:*:*:*:*:*"
],
"vendor_product": "tenable:tenable.sc",
"extracted_events": [
{
"range": [
{
"introduced": "5.14.0"
},
{
"fixed": "5.20.0"
},
{
"introduced": "5.16.0"
},
{
"fixed": "202201.1"
}
],
"source": "CPE_RANGE"
}
]
},
{
"cpes": [
"cpe:2.3:o:apple:mac_os_x:10.15.7:*:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-001:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-002:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-003:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-004:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-005:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-006:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-007:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-008:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-001:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-002:*:*:*:*:*:*",
"cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-003:*:*:*:*:*:*"
],
"vendor_product": "apple:mac_os_x",
"extracted_events": [
{
"range": [
{
"introduced": "10.15.7"
},
{
"last_affected": "10.15.7"
},
{
"introduced": "10.15.7-security_update_2020\\-001"
},
{
"last_affected": "10.15.7-security_update_2020\\-001"
},
{
"introduced": "10.15.7-security_update_2021\\-001"
},
{
"last_affected": "10.15.7-security_update_2021\\-001"
},
{
"introduced": "10.15.7-security_update_2021\\-002"
},
{
"last_affected": "10.15.7-security_update_2021\\-002"
},
{
"introduced": "10.15.7-security_update_2021\\-003"
},
{
"last_affected": "10.15.7-security_update_2021\\-003"
},
{
"introduced": "10.15.7-security_update_2021\\-004"
},
{
"last_affected": "10.15.7-security_update_2021\\-004"
},
{
"introduced": "10.15.7-security_update_2021\\-005"
},
{
"last_affected": "10.15.7-security_update_2021\\-005"
},
{
"introduced": "10.15.7-security_update_2021\\-006"
},
{
"last_affected": "10.15.7-security_update_2021\\-006"
},
{
"introduced": "10.15.7-security_update_2021\\-007"
},
{
"last_affected": "10.15.7-security_update_2021\\-007"
},
{
"introduced": "10.15.7-security_update_2021\\-008"
},
{
"last_affected": "10.15.7-security_update_2021\\-008"
},
{
"introduced": "10.15.7-security_update_2022\\-001"
},
{
"last_affected": "10.15.7-security_update_2022\\-001"
},
{
"introduced": "10.15.7-security_update_2022\\-002"
},
{
"last_affected": "10.15.7-security_update_2022\\-002"
},
{
"introduced": "10.15.7-security_update_2022\\-003"
},
{
"last_affected": "10.15.7-security_update_2022\\-003"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*"
],
"vendor_product": "debian:debian_linux",
"extracted_events": [
{
"range": [
{
"introduced": "10.0"
},
{
"last_affected": "10.0"
},
{
"introduced": "11.0"
},
{
"last_affected": "11.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*",
"cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*"
],
"vendor_product": "fedoraproject:fedora",
"extracted_events": [
{
"range": [
{
"introduced": "34"
},
{
"last_affected": "34"
},
{
"introduced": "35"
},
{
"last_affected": "35"
},
{
"introduced": "36"
},
{
"last_affected": "36"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:communications_operations_monitor:4.0:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:communications_operations_monitor:4.3:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:communications_operations_monitor:4.4:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:communications_operations_monitor:5.0:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:communications_operations_monitor",
"extracted_events": [
{
"range": [
{
"introduced": "4.0"
},
{
"last_affected": "4.0"
},
{
"introduced": "4.3"
},
{
"last_affected": "4.3"
},
{
"introduced": "4.4"
},
{
"last_affected": "4.4"
},
{
"introduced": "5.0"
},
{
"last_affected": "5.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:http_server",
"extracted_events": [
{
"range": [
{
"introduced": "12.2.1.3.0"
},
{
"last_affected": "12.2.1.3.0"
},
{
"introduced": "12.2.1.4.0"
},
{
"last_affected": "12.2.1.4.0"
}
],
"source": "CPE_STRING"
}
]
},
{
"cpes": [
"cpe:2.3:a:oracle:instantis_enterprisetrack:17.1:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:instantis_enterprisetrack:17.2:*:*:*:*:*:*:*",
"cpe:2.3:a:oracle:instantis_enterprisetrack:17.3:*:*:*:*:*:*:*"
],
"vendor_product": "oracle:instantis_enterprisetrack",
"extracted_events": [
{
"range": [
{
"introduced": "17.1"
},
{
"last_affected": "17.1"
},
{
"introduced": "17.2"
},
{
"last_affected": "17.2"
},
{
"introduced": "17.3"
},
{
"last_affected": "17.3"
}
],
"source": "CPE_STRING"
}
]
}
]
}
},
"related_cves": [
{
"value": "CVE-2021-44224",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 436128,
"published_at": "2021-12-20T12:15:07.393+00:00"
}