dbcve.org
Websphere Application ServerApplication · Ibm

CVE-2021-38951

HIGH · 7.5 CVSS v3.1 Published 2021-12-09
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
IBM WebSphere Application Server 7.0, 8.0, 8.5, and 9.0 is vulnerable to a denial of service, caused by sending a specially-crafted request. A remote attacker could exploit this vulnerability to cause the server to consume all available CPU resources. IBM X-Force ID: 211405.

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

IBM WebSphere Application Server versions 7.0, 8.0, 8.5, and 9.0 contains a denial of service vulnerability where a remote attacker can send a specially-crafted request that causes the server to consume all available CPU resources, potentially rendering the application unavailable.

MitigationApply the IBM fix/patch for CVE-2021-38951 (contact IBM support for patch availability), and consider implementing rate limiting or request filtering at the network edge to block malicious request patterns until the patch can be applied.

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
Websphere Application ServerApplication
Affected:= 7.0= 8.0= 8.5= 9.0

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
None
Integrity
None
Availability
High

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

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 IBM WebSphere Application Server installation
    Locate the WebSphere installation directory and check for the presence of WebSphere binaries. Common paths include /opt/IBM/WebSphere/AppServer or C:\IBM\WebSphere\AppServer. Look for the product.ini or version files in the installation root.
    Affected if IBM WebSphere Application Server is installed on the system
  2. Determine the installed WebSphere version
    Run the versionInfo command from the WebSphere bin directory: versionInfo.sh (Linux/Unix) or versionInfo.bat (Windows). Alternatively, check the product.properties or aboutWebSphere.properties files in the installation properties directory.
    Affected if The version reported is 7.0.x, 8.0.x, 8.5.x, or 9.0.x (any minor version within these major version lines)
  3. Verify network accessibility of the WebSphere HTTP ports
    Check the WebSphere HTTP transport configuration in the admin console or server.xml. Identify the ports WebSphere is listening on (default 9080, 9443, etc.) and determine if these ports are exposed to untrusted networks or the public internet.
    Affected if The WebSphere HTTP ports are accessible from untrusted network sources (not limited to localhost or internal trusted networks)
  4. Monitor for unusual CPU consumption
    Use system monitoring tools (top, htop on Linux; Task Manager or Performance Monitor on Windows) to observe CPU usage by the WebSphere Java process (typically java.exe or java). Look for sustained 100% CPU usage or CPU spikes not corresponding to normal load patterns.
    Affected if The WebSphere process shows abnormally high CPU usage that persists or spikes without corresponding legitimate load

A system is affected if it runs IBM WebSphere Application Server versions 7.0.x, 8.0.x, 8.5.x, or 9.0.x with HTTP ports exposed to untrusted networks.

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the IBM fix/patch for CVE-2021-38951 (contact IBM support for patch availability), and consider implementing rate limiting or request filtering at the network edge to block malicious request patterns until the patch can be applied.

Fix this in Websphere Application Server Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing8.0 h
  • Review / QA3.0 h
20.0 hours of engineering $3,420
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,472.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-38951 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2021-38951 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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