Apm Java AgentApplication · Elastic
CVE-2021-37942
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 · uneditedA local privilege escalation issue was found with the APM Java agent, where a user on the system could attach a malicious plugin to an application running the APM Java agent. By using this vulnerability, an attacker could execute code at a potentially higher level of permissions than their user typically has access to.
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 confidenceA local privilege escalation vulnerability exists in the APM Java agent where an authenticated user on the system can attach a malicious plugin to an application running the agent. This allows the attacker to execute code with elevated privileges beyond what their user account typically has access to.
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
Apm Java AgentApplication
>= 1.18.0, <= 1.27.0CVSS 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
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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 checksWork through these to decide whether this CVE applies to you.
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Locate the Elastic APM Java Agent JAR fileSearch the filesystem for 'elastic-apm-agent*.jar' using find / -name "elastic-apm-agent*.jar" 2>/dev/null or check application classpath and startup scripts for -javaagent:/path/to/elastic-apm-agent*.jarAffected if The agent JAR file exists in the environment
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Determine the installed APM agent versionRun: jar -f /path/to/elastic-apm-agent*.jar META-INF/MANIFEST.MF | grep Implementation-Version, or check the filename which may contain the version numberAffected if The version falls within >= 1.18.0 and <= 1.27.0
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Identify if plugin loading is enabledCheck the APM agent configuration for 'plugins_dir' or 'enable_plugin_support' settings in apm.config, environment variables, or JVM system properties. Also examine if a plugins/ directory exists alongside the agent JARAffected if Plugin loading is enabled and a plugins directory is present or configurable
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Verify plugin directory access controlsInspect the plugin directory permissions and ownership. Check if unprivileged users have write access to directories from which the agent loads pluginsAffected if Untrusted or low-privilege users can write to or add plugins to directories the APM agent uses
Environment is affected if Elastic APM Java Agent version 1.18.0 through 1.27.0 is installed with plugin loading enabled and insufficient access controls on plugin directories, allowing authenticated users to inject malicious plugins for privilege escalation.
Generated from the published advisory. Verify against your own configuration.
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 · scopedApply the vendor-provided patch for the APM Java agent and review plugin loading mechanisms to ensure only trusted/validated plugins can be attached. Implement least-privilege access controls for users running instrumented applications.
APM Java Agent version 1.28.0 or later
- Identify all systems running APM Java Agent versions 1.18.0 through 1.27.0
- Stop the applications running the vulnerable APM Java Agent
- Upgrade the APM Java Agent to version 1.28.0 or later
- Verify the upgrade by checking the agent version in use
- Restart the applications with the updated agent
- Confirm the plugin attachment mechanism now properly validates and restricts plugins
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Apm Java Agent
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-37942 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-37942 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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