Security readout for executives and security teams
Plain-English summary
Certain Phoenix Contact FL MGUARD 1102 and 1105 devices can leak memory when remote logging is enabled. Over time, this can degrade or interrupt device availability. The business concern is operational disruption in environments that rely on these security appliances, especially if affected firmware is still deployed.
Executive priority
Treat this as a high-priority availability risk for environments using affected FL MGUARD devices. It is most urgent where these appliances protect production, industrial, or remote network segments and remote logging is active.
Technical view
CVE-2021-34598 is a CWE-401 memory-release flaw in FL MGUARD remote logging. Sources state syslog-ng-related data structures are not released when remote logging is active. CVSS 3.1 is 7.5, network reachable, low complexity, no privileges or user interaction, with high availability impact only.
Likely exposure
Exposure is limited to Phoenix Contact FL MGUARD 1102 and 1105 running versions 1.4.0, 1.4.1, or 1.5.0, particularly where remote logging is enabled. The structured affected list in the bundle appears incomplete, so confirm against the vendor advisory.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. CVSS indicates unauthenticated network reachability and availability impact, but the sources do not provide exploit details or confirm public weaponization.
Researcher notes
The key trigger condition is active remote logging. The reported impact is availability only: no confidentiality or integrity impact is claimed. Evidence is limited to the CVE data and Phoenix Contact advisory reference; validate exact fixed versions and operational guidance directly with the vendor source.
Mitigation direction
- Review Phoenix Contact VDE-2021-046 for supported fixes or workarounds.
- Inventory FL MGUARD 1102 and 1105 devices and firmware versions.
- Identify whether remote logging is enabled on affected devices.
- Assess temporary remote logging changes only against vendor guidance and operational needs.
- Monitor affected devices for memory growth, restarts, or service degradation.
- Prioritize vendor-approved firmware remediation where available.
Validation and detection
- Confirm device model is FL MGUARD 1102 or 1105.
- Confirm firmware is 1.4.0, 1.4.1, or 1.5.0.
- Verify whether remote logging is active.
- Review device health for memory pressure or availability symptoms.
- Check vendor advisory status before declaring remediation complete.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-401: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-34598 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://cert.vde.com/en/advisories/VDE-2021-046/CVE reference · x_refsource_CONFIRM
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Missing Release of Memory after Effective Lifetime
Missing Release of Memory after Effective Lifetime represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.