BlackTreeCVE Intelligence
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Full vulnerability report · 2022
CVE-2022-22721High confidence

core: Possible buffer overflow with very large or unlimited LimitXMLRequestBody

Apache Software Foundation · Apache HTTP Server

9.1CriticalCVSS 3.1
Recommended action
Within 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityCriticalOperational priority:Critical, unchanged from published severity.unchanged

Evidence used

  • No CISA KEV confirmation is currently recorded.
  • The selected CVSS metric records a network-reachable, unauthenticated path with no user interaction.
  • EPSS is 41.71% for the current model date.

Compensating controls

  • Validate the affected product branch and deploy the verified fixed release.
  • Restrict the affected network interface to trusted sources where business-safe.
  • Monitor vendor guidance and exploitation sources for a material change.

Verification

  1. Confirm that the asset runs Apache Software Foundation Apache HTTP Server and falls inside the recorded affected range.
  2. Verify the installed build against the product-specific fixed version after deployment.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Distribution package intelligence

Release-specific package status

Alpine, Debian findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.

7 package states
Repository candidate not checked

A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.

Distribution releaseSource packageVendor stateFixed versionEvidence
Alpine v3.23v3.23 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.53-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.22v3.22 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.53-r0Alpine Security Database ↗Source updated 3 Oct 2026
Alpine v3.21v3.21 · mainapache2Vendor fix publishedAlpine records a security fix at this version. An absent entry does not mean the package is unaffected.2.4.53-r0Alpine Security Database ↗Source updated 3 Oct 2026
Debian trixietrixie · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.53-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian bookwormbookworm · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.53-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian forkyforky · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.53-1Debian Security Tracker ↗Source updated 6 Oct 2026
Debian sidsid · sourceapache2Vendor fix publishedDebian records a fixed source-package version for this release.2.4.53-1Debian Security Tracker ↗Source updated 6 Oct 2026
Direct vendor intelligence

Authoritative vendor CSAF and VEX advisories

Structured product status and remediation from the issuing vendor. Product-state explanations are always visible; large lists can be searched or downloaded.

1 current
CVE-2022-22721 · CSAF 2.0 · revision 3 · finalRed Hat Product Securityhttpd: core: Possible buffer overflow with very large or unlimited LimitXMLRequestBody
22 known affected

The vendor explicitly identifies these products as affected by this CVE.

  • httpd as a component of Red Hat Enterprise Linux 6
  • httpd-devel as a component of Red Hat Enterprise Linux 6
  • httpd-manual as a component of Red Hat Enterprise Linux 6
  • httpd-tools as a component of Red Hat Enterprise Linux 6
  • httpd.src as a component of Red Hat Enterprise Linux 6
  • mod_ssl as a component of Red Hat Enterprise Linux 6
  • httpd as a component of Red Hat Enterprise Linux 7
  • httpd-devel as a component of Red Hat Enterprise Linux 7
  • httpd-manual as a component of Red Hat Enterprise Linux 7
  • httpd-tools as a component of Red Hat Enterprise Linux 7
  • httpd.src as a component of Red Hat Enterprise Linux 7
  • mod_ldap as a component of Red Hat Enterprise Linux 7
Summary
A flaw was found in httpd, where it incorrectly limits the value of the LimitXMLRequestBody option. This issue can lead to an integer overflow and later causes an out-of-bounds write.
Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the httpd daemon will be restarted automatically.
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2022-27864

No EUVD known-exploited evidence

ENISA has published the identifier mapping but no EUVD description has been stored yet.

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
Not supplied in the stored EUVD record
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 72 hours

Critical technical impact with a remotely reachable, unauthenticated path; no CISA KEV confirmation is currently recorded.

Patch available
01

What, why and how

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.

What

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.

Why

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

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.

Why

The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Integer Overflow or Wraparound → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface
Network
Privileges required
None: unauthenticated exploitation is possible
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-190 ↗

CWE-190: Integer Overflow or Wraparound. The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
NetworkUnauthenticatedCWE-190
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

BSI · German · WID-SEC-2022-1057Apple macOS: Mehrere Schwachstellen

Ein entfernter, anonymer, authentisierter oder lokaler Angreifer kann mehrere Schwachstellen in Apple macOS ausnutzen, um seine Privilegien zu erweitern, beliebigen Code auszuführen, Sicherheitsmaßnahmen zu umgehen, einen Denial-of-Service-Zustand herbeizuführen, vertrauliche Informationen offenzulegen und im schlimmsten Fall das System zu kompromittieren.

Official advisory ↗
BSI · German · WID-SEC-2022-1335Xerox FreeFlow Print Server: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Xerox FreeFlow Print Server ausnutzen, um die Vertraulichkeit, Verfügbarkeit und Integrität des Systems zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2022-0432Xerox FreeFlow Print Server: Mehrere Schwachstellen

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Xerox FreeFlow Print Server ausnutzen, um die Vertraulichkeit, Verfügbarkeit und Integrität zu gefährden.

Official advisory ↗
BSI · German · WID-SEC-2022-0302Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen Ausführen von beliebigem Programmcode mit Administratorrechten

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Xerox FreeFlow Print Server ausnutzen, um beliebigen Programmcode auszuführen, einen Cross-Site-Scripting-Angriff durchzuführen, Informationen offenzulegen, einen Denial-of-Service-Zustand zu verursachen oder Dateien zu manipulieren.

Official advisory ↗
BSI · German · WID-SEC-2022-0646Apache HTTP Server: Mehrere Schwachstellen

Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Apache HTTP Server ausnutzen, um beliebigen Programmcode auszuführen, Informationen offenzulegen, Dateien zu manipulieren oder einen Denial of Service Zustand herbeizuführen.

Official advisory ↗
BSI · German · WID-SEC-2024-1591Juniper JUNOS: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Juniper JUNOS ausnutzen, um einen Denial of Service zu verursachen, Informationen offenzulegen, Privilegien zu erweitern und Sicherheitsmechanismen inklusive zu umgehen.

Official advisory ↗
Cyber Security Agency of Singapore · English · CSA-SB-20220316Security Bulletin 16 Mar 2022

The Cyber Security Agency of Singapore included this CVE in its official Security Bulletin 16 Mar 2022, published on 16 March 2022. Open the linked bulletin for the product, severity and reference information published in that issue.

Official advisory ↗
CERT-FR · French · CERTFR-2024-AVI-0575Multiples vulnérabilités dans les produits Juniper Networks

d?id=CVE-2022-21454 Référence CVE CVE-2022-21460 https://www.cve.org/CVERecord?id=CVE-2022-21460 Référence CVE CVE-2022-21589 https://www.cve.org/CVERecord?id=CVE-2022-21589 Référence CVE CVE-2022-21592 https://www.cve.org/CVERecord?id=CVE-2022-21592 Référence CVE CVE-2022-21595 https://www.cve.org/CVERecord?id=CVE-2022-21595 Référence CVE CVE-2022-21608 https://www.cve.org/CVERecord?id=CVE-2022-21608 Référence CVE CVE-2022-21617 https://www.cve.org/CVERecord?id=CVE-2022-21617 Référence CVE CVE-2022-22719 https://www.cve.org/CVERecord?id=CVE-2022-22719 Référence CVE CVE-2022-22720 https://www.cve.org/CVERecord?id=CVE-2022-22720 Référence CVE CVE-2022-22721 https://www.cve.org/CVERecord?id=CVE-2022-22721 Référence CVE CVE-2022-22822 https://www.cve.org/CVERecord?id=CVE-2022-22822 Référence CVE CVE-2022-22823 https://www.cve.org/CVERecord?id=CVE-2022-22823 Référence CVE CVE-2022-22824 https://www.cve.org/CVERecord?id=CVE-2022-22824 Référence CVE CVE-2022-23852 https://www.cve.org/CVERecord?id=CVE-2022-23852 Référence CVE CVE-2022-23943 https://www.cve.org/CVERecord?id=CVE-2022-23943 Référence CVE CVE-2022-25147 https://www.cve.org/CVERecord?id=CVE-2022-25147 Référence CVE CVE-2022-25235 https://www.cve.org/CVERecord?id=CVE-2022-25235 Référence CVE CVE-2022-25236 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-467Multiples vulnérabilités dans le noyau Linux de SUSE

d?id=CVE-2022-22589 Référence CVE CVE-2022-22663 https://www.cve.org/CVERecord?id=CVE-2022-22663 Référence CVE CVE-2022-22665 https://www.cve.org/CVERecord?id=CVE-2022-22665 Référence CVE CVE-2022-22673 https://www.cve.org/CVERecord?id=CVE-2022-22673 Référence CVE CVE-2022-22674 https://www.cve.org/CVERecord?id=CVE-2022-22674 Référence CVE CVE-2022-22675 https://www.cve.org/CVERecord?id=CVE-2022-22675 Référence CVE CVE-2022-22677 https://www.cve.org/CVERecord?id=CVE-2022-22677 Référence CVE CVE-2022-22719 https://www.cve.org/CVERecord?id=CVE-2022-22719 Référence CVE CVE-2022-22720 https://www.cve.org/CVERecord?id=CVE-2022-22720 Référence CVE CVE-2022-22721 https://www.cve.org/CVERecord?id=CVE-2022-22721 Référence CVE CVE-2022-23308 https://www.cve.org/CVERecord?id=CVE-2022-23308 Référence CVE CVE-2022-24765 https://www.cve.org/CVERecord?id=CVE-2022-24765 Référence CVE CVE-2022-26693 https://www.cve.org/CVERecord?id=CVE-2022-26693 Référence CVE CVE-2022-26694 https://www.cve.org/CVERecord?id=CVE-2022-26694 Référence CVE CVE-2022-26697 https://www.cve.org/CVERecord?id=CVE-2022-26697 Référence CVE CVE-2022-26698 https://www.cve.org/CVERecord?id=CVE-2022-26698 Référence CVE CVE-2022-26700 https://www.cve.org/CVERecord?id=CVE-2022-26700 Référence CVE CVE-2022-26701 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-466Multiples vulnérabilités dans les produits Apple

d?id=CVE-2022-22589 Référence CVE CVE-2022-22663 https://www.cve.org/CVERecord?id=CVE-2022-22663 Référence CVE CVE-2022-22665 https://www.cve.org/CVERecord?id=CVE-2022-22665 Référence CVE CVE-2022-22673 https://www.cve.org/CVERecord?id=CVE-2022-22673 Référence CVE CVE-2022-22674 https://www.cve.org/CVERecord?id=CVE-2022-22674 Référence CVE CVE-2022-22675 https://www.cve.org/CVERecord?id=CVE-2022-22675 Référence CVE CVE-2022-22677 https://www.cve.org/CVERecord?id=CVE-2022-22677 Référence CVE CVE-2022-22719 https://www.cve.org/CVERecord?id=CVE-2022-22719 Référence CVE CVE-2022-22720 https://www.cve.org/CVERecord?id=CVE-2022-22720 Référence CVE CVE-2022-22721 https://www.cve.org/CVERecord?id=CVE-2022-22721 Référence CVE CVE-2022-23308 https://www.cve.org/CVERecord?id=CVE-2022-23308 Référence CVE CVE-2022-24765 https://www.cve.org/CVERecord?id=CVE-2022-24765 Référence CVE CVE-2022-26693 https://www.cve.org/CVERecord?id=CVE-2022-26693 Référence CVE CVE-2022-26694 https://www.cve.org/CVERecord?id=CVE-2022-26694 Référence CVE CVE-2022-26697 https://www.cve.org/CVERecord?id=CVE-2022-26697 Référence CVE CVE-2022-26698 https://www.cve.org/CVERecord?id=CVE-2022-26698 Référence CVE CVE-2022-26700 https://www.cve.org/CVERecord?id=CVE-2022-26700 Référence CVE CVE-2022-26701 https://www.cve.org/CVERecord?id=

Official advisory ↗
CERT-FR · French · CERTFR-2022-AVI-241Multiples vulnérabilités dans Apache HTTP Server

De multiples vulnérabilités ont été découvertes dans Apache HTTP Server. Elles permettent à un attaquant de provoquer un problème de sécurité non spécifié par l'éditeur, un déni de service à distance et un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2022-001480Apache HTTP Server における整数オーバーフローの脆弱性

Apache HTTP Server の LimitXMLRequestBody には、32 bit システムで 350MB を超えるリクエストボディを許可するように設定している場合、整数オーバーフローの脆弱性、および境界外書き込みに関する脆弱性が存在します。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-5588Apache HTTP Server 보안 업데이트 권고

Apache HTTP Server에서 발생하는 버퍼오버플로우 취약점(CVE-2022-22721)

Official advisory ↗
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
Fixed
Action
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the httpd daemon will be restarted automatically.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 14 Mar 2022 · Last source change 3 Aug 2024, 03:21 UTC · CWE-190 · Integer Overflow or Wraparound

CVE recordCVE.org · 5.1
CVSS sourceNIST NVD
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2022-27864
Product sourceVendor CSAF · Red Hat Product Security
Remediation sourceVendor CSAF · Red Hat Product Security
CWE sourceCNA
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    Apache HTTP Server 2.4 ≤ 2.4.52 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    Apache HTTP Server 2.4 ≤ 2.4.52 · Fixed: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Applications using the APR libraries, such as httpd, must be restarted for this update to take effect. After installing the updated packages, the httpd daemon will be restarted automatically.
    Red Hat Product Security ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
Fixed release recorded from official guidance
ENISA EUVD · EUVD-2022-27864↗Red Hat Product Security security advisory↗CVE authority or vendor reference↗Patch or update reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2022-22721 · cve.blacktree.nl