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Websphere Application ServerApplication · Ibm

CVE-2020-4534

HIGH · 8.8 CVSS v3.1 Published 2020-08-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
90/100
Remediation priority · Urgent
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 could allow a local authenticated attacker to gain elevated privileges on the system, caused by improper handling of UNC paths. By scheduling a task with a specially-crafted UNC path, an attacker could exploit this vulnerability to execute arbitrary code with higher privileges. IBM X-Force ID: 182808.

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 through 9.0 contain a local privilege escalation vulnerability due to improper handling of UNC paths in the task scheduling functionality. An authenticated local attacker can schedule a task with a specially-crafted UNC path pointing to a malicious executable on a remote network share, causing arbitrary code to execute with elevated privileges.

MitigationApply the IBM security patch for APAR PH25016 (or subsequent superseding patches) to address this vulnerability. Additionally, restrict the ability to schedule tasks to only trusted, non-privileged accounts and consider disabling UNC path support in scheduled tasks if not required by the application.

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
Local
Complexity
Low
Privileges
Low
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/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 the installed IBM WebSphere Application Server version
    Run the versionInfo command from the bin directory of the WebSphere installation: versionInfo.bat (Windows) or versionInfo.sh (Linux/Unix). Alternatively, check the installedApps directory or the product.install.root directory for version metadata files.
    Affected if The installed version is 7.0, 8.0, 8.5, or 9.0 exactly as listed in the affected versions.
  2. Verify if task scheduling functionality is configured
    Access the WebSphere Administrative Console and navigate to Resources > Schedules. Alternatively, check for scheduler configuration in the was.config or scheduler.xml configuration files within the config directory of the WebSphere profile.
    Affected if A scheduler service is configured and enabled in the WebSphere environment.
  3. Confirm the user role has permission to create or modify scheduled tasks
    In the WebSphere Administrative Console, go to Users and Groups > Administrative User and Group Management. Verify if the user account in question has the TaskManagerServer or ScheduleAdmin role. Check security.xml for authorization settings related to task scheduling.
    Affected if The authenticated user has privileges to create, modify, or schedule tasks through the WebSphere task scheduling mechanism.
  4. Inspect task scheduler configuration for UNC path support
    Examine the scheduler configuration files (typically in the config/cells/ directory under the WebSphere profile) for any task definitions that reference UNC paths (paths beginning with \\). Use the administrative console to list all scheduled tasks and inspect their executable paths.
    Affected if UNC path support is enabled in the scheduler configuration, allowing tasks to point to network shares (\\server\share\executable).

A user is affected if they run IBM WebSphere Application Server versions 7.0 through 9.0 with task scheduling enabled and have users with task scheduling permissions, particularly if UNC paths are permitted in scheduled task definitions.

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 security patch for APAR PH25016 (or subsequent superseding patches) to address this vulnerability. Additionally, restrict the ability to schedule tasks to only trusted, non-privileged accounts and consider disabling UNC path support in scheduled tasks if not required by the application.

Fix this in Websphere Application Server Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,780
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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-2020-4534 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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