dbcve.org
HTTP ServerWeb server / proxy · Apache

CVE-2022-30556

HIGH · 7.5 CVSS v3.1 Published 2022-06-09
Fix available
A fix is available. Upgrade to 2.4.54 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Apache HTTP Server 2.4.53 and earlier may return lengths to applications calling r:wsread() that point past the end of the storage allocated for the buffer.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Apache HTTP Server 2.4.53 and earlier contains a buffer over-read vulnerability in the r:wsread() function used for WebSocket connections. The function may return length values that point past the end of the allocated buffer, potentially exposing sensitive memory contents to applications.

MitigationUpgrade to Apache HTTP Server 2.4.54 or later to remediate this vulnerability.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
HTTP ServerWeb server / proxy
Affected:< 2.4.54
FedoraOperating system
Affected:= 35= 36
Clustered Data OntapApplication
Affected:all versions

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Apache HTTP Server installation and version
    Run 'httpd -v' or 'apache2 -v' to get the server version, or check the package manager (e.g., 'rpm -q httpd' or 'dpkg -l apache2')
    Affected if The installed version is earlier than 2.4.54 (e.g., 2.4.53, 2.4.52, etc.)
  2. Confirm WebSocket module is loaded
    Check for loaded WebSocket-related modules by running 'httpd -M' or 'apache2ctl -M' and look for mod_websocket, mod_proxy_wstunnel, or similar WebSocket modules
    Affected if WebSocket support modules (mod_websocket, mod_proxy_wstunnel) are loaded and active
  3. Check for active WebSocket configurations
    Inspect Apache configuration files (httpd.conf, ssl.conf, or included config files) for 'ProxyPass' or 'ProxyPassReverse' directives using the 'ws://' or 'wss://' protocol, or WebSocket-related RewriteRule patterns with 'ws:' flag
    Affected if The server is configured to proxy or handle WebSocket connections (ws:// or wss:// URLs)
  4. Verify running service binary version
    If unable to get version via httpd -v, check the running process binary directly: 'ps aux | grep httpd' then 'ls -l /proc/<pid>/exe' or check the binary file directly with '/usr/sbin/httpd -V'
    Affected if The binary version is confirmed to be < 2.4.54

A system is affected if Apache HTTP Server version is earlier than 2.4.54 AND WebSocket connections (ws:// or wss://) are being processed by the server.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.4.54 or later
Fixed in 2.4.54
Interim mitigation

Upgrade to Apache HTTP Server 2.4.54 or later to remediate this vulnerability.

Recommended fix High confidence

Apache HTTP Server 2.4.54 or later

  1. 1. Back up your Apache HTTP Server configuration files (httpd.conf, any included config files, and SSL certificates)
  2. 2. For RHEL/CentOS/Rocky Linux: Run 'sudo yum update httpd' or 'sudo dnf update httpd'
  3. 3. For Debian/Ubuntu: Run 'sudo apt update && sudo apt install apache2'
  4. 4. For Fedora: Run 'sudo dnf update httpd'
  5. 5. Verify the installed version is 2.4.54 or later by running 'httpd -v' or 'apache2 -v'
  6. 6. Restore your backed-up configuration files if they were overwritten
  7. 7. Test the configuration with 'httpd -t' or 'apache2ctl configtest'
  8. 8. Restart the Apache service with 'sudo systemctl restart httpd' or 'sudo systemctl restart apache2'
Caveat Minor version upgrades typically maintain configuration compatibility; review Apache changelog for any module-specific changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in HTTP Server Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-30556 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data