CVE-2021-34598
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 · uneditedIn Phoenix Contact FL MGUARD 1102 and 1105 in Versions 1.4.0, 1.4.1 and 1.5.0 the remote logging functionality is impaired by the lack of memory release for data structures from syslog-ng when remote logging is active
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 · moderate confidenceA memory leak vulnerability exists in Phoenix Contact FL MGUARD 1102 and 1105 devices running versions 1.4.0, 1.4.1, and 1.5.0. When remote logging is enabled, the syslog-ng component fails to release memory for data structures, leading to gradual memory exhaustion that can impair remote logging functionality and potentially cause device instability.
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= 1.4.0= 1.4.1= 1.5.0= 1.4.0= 1.4.1= 1.5.0CVSS 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
- 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 checksWork through these to decide whether this CVE applies to you.
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Identify the MGUARD device modelAccess the device web interface or CLI and locate the model information. Look for 'FL MGUARD 1102' or 'FL MGUARD 1105' in the device status or system information page.Affected if The device model is FL MGUARD 1102 or FL MGUARD 1105.
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Check the installed firmware versionIn the device web interface, navigate to the System or Status section to view the firmware version. Alternatively, use the CLI command that displays system information to retrieve the firmware version.Affected if The firmware version is 1.4.0, 1.4.1, or 1.5.0.
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Verify if remote logging is enabledIn the device web interface, navigate to the Logging or Syslog configuration section. Check whether remote logging to an external syslog server is configured and enabled.Affected if Remote logging (syslog) is enabled and pointing to a remote syslog server.
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Monitor memory usage on the deviceAccess the device status page or use CLI commands to view system resources. Look for abnormally high or steadily increasing memory usage, particularly in the syslog-ng process.Affected if Memory usage is abnormally high or continuously increasing, especially if remote logging has been active for some time.
The device is affected if it is an MGUARD 1102 or 1105 running firmware version 1.4.0, 1.4.1, or 1.5.0 with remote logging enabled, and elevated memory consumption is observed.
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.
From vendor dataUpdate the MGUARD firmware to a version beyond 1.5.0 that contains the memory management fix for syslog-ng, and verify that remote logging operates correctly without memory leaks after the update.
- Consultation4.0 h
- Implementation3.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34598 — 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-2021-34598 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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