CVE-2022-22721 | core: Possible buffer overflow with very large or unlimited LimitXMLRequestBody

If LimitXMLRequestBody is set to allow request bodies larger than 350MB (defaults to 1M) on 32 bit systems an integer overflow happens which later causes out of bounds writes. This issue affects Apache HTTP Server 2.4.52 and earlier.

Published: 2022-03-14 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-22721 is rated High Risk (75.9/100): CVSS Critical severity, with high exploitation likelihood (EPSS 41.86%, 99th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. EPSS rose +28.39% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-22721

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 13.47% 41.86% +28.39%
2 2026-04-30 13.16% 13.47% +0.31%
3 2026-03-04 — 13.16% —

Full EPSS history (64 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-22721

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.2 [email protected]
5.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:N/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 4.9 [email protected]

Weakness enumeration for CVE-2022-22721

OS Trackers for CVE-2022-22721

vendor priority summary link
alpine critical CVE-2022-22721: 1 source package rows (apache2); 8 state rows across 8 repos (3.12-main, 3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 8, open 0. https://security.alpinelinux.org/vuln/CVE-2022-22721
debian not yet assigned CVE-2022-22721 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-22721
gentoo high CVE-2022-22721: 1 GLSA(s) (202208-20), 2 atom(s) (app-admin/apache-tools, www-servers/apache); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-22721
redhat medium — https://access.redhat.com/security/cve/CVE-2022-22721
suse high CVE-2022-22721 severity important: SUSE including 313 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 585 product×package rows across 71 product lines (HPE Helion OpenStack 8, Image SLES15-SP3-EC2-HVM, … (71 product lines)): Fixed 354, Known Affected 231. https://www.suse.com/security/cve/CVE-2022-22721/
ubuntu low CVE-2022-22721 low priority: Ubuntu including 1 source packages (apache2), 7 status rows across 7 suites (bionic, focal, impish, jammy, trusty, upstream, xenial): released 7. https://ubuntu.com/security/CVE-2022-22721

Affected software / configurations for CVE-2022-22721

Vendor Product Version Raw CPE
apache http_server <= 2.4.52 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*
fedoraproject fedora 34 cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
fedoraproject fedora 36 cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
oracle enterprise_manager_ops_center 12.4.0.0 cpe:2.3:a:oracle:enterprise_manager_ops_center:12.4.0.0:*:*:*:*:*:*:*
oracle http_server 12.2.1.3.0 cpe:2.3:a:oracle:http_server:12.2.1.3.0:*:*:*:*:*:*:*
oracle http_server 12.2.1.4.0 cpe:2.3:a:oracle:http_server:12.2.1.4.0:*:*:*:*:*:*:*
oracle zfs_storage_appliance_kit 8.8 cpe:2.3:a:oracle:zfs_storage_appliance_kit:8.8:*:*:*:*:*:*:*
apple mac_os_x >= 10.15, < 10.15.7 cpe:2.3:o:apple:mac_os_x:*:*:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2020-001:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-001:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-002:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-003:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-004:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-005:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-006:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-007:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2021-008:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-001:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-002:*:*:*:*:*:*
apple mac_os_x 10.15.7 cpe:2.3:o:apple:mac_os_x:10.15.7:security_update_2022-003:*:*:*:*:*:*
apple macos >= 11.0, < 11.6.6 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*
apple macos >= 12.0, < 12.4 cpe:2.3:o:apple:macos:*:*:*:*:*:*:*:*

References for CVE-2022-22721

URL Tags
http://seclists.org/fulldisclosure/2022/May/33 Third Party Advisory
http://seclists.org/fulldisclosure/2022/May/35 Third Party Advisory
http://seclists.org/fulldisclosure/2022/May/38 Third Party Advisory
http://www.openwall.com/lists/oss-security/2022/03/14/2 Mailing List Third Party Advisory
https://httpd.apache.org/security/vulnerabilities_24.html Vendor Advisory
https://lists.debian.org/debian-lts-announce/2022/03/msg00033.html Mailing List Third Party Advisory
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 Third Party Advisory
https://security.netapp.com/advisory/ntap-20220321-0001/ Third Party Advisory
https://support.apple.com/kb/HT213255 Third Party Advisory
https://support.apple.com/kb/HT213256 Third Party Advisory
https://support.apple.com/kb/HT213257 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2022.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
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