Security readout for executives and security teams
This vulnerability can let an unauthenticated network user disrupt vulnerable CODESYS V2 runtime systems. The reported impact is availability only: PLC programs may stop, memory may leak, or legitimate clients may be blocked from communicating with the PLC. Exposure is most relevant where affected CODESYS V2 runtimes or PLCWinNT are reachable over a network, especially from untrusted or poorly segmented networks. The bundle does not establish exposure for products beyond the named CODESYS components. Prioritize remediation for production control environments where downtime affects safety, operations, or revenue. The issue is not described as data theft or code execution, but unauthenticated disruption of PLC availability can still create material operational risk. Mitigation focus: Upgrade affected CODESYS V2 Runtime Toolkit and PLCWinNT installations to V2.4.7.56 or later.; Check CODESYS and OEM vendor guidance for device-specific update paths.; Restrict network access to PLC runtime services to trusted engineering and control hosts..
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
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CWE-755: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-34593 mapping review
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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
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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://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16877&token=8faab0fc1e069f4edfca5d5aba8146139f67a175&download=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.
Improper Handling of Exceptional Conditions
Improper Handling of Exceptional Conditions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.