CVE-2021-34593

CODESYS V2 runtime: unauthenticated invalid requests may result in denial-of-service

HIGH
7.5
CVSS Score
Published: October 26, 2021 at 09:55 AM UTC
Updated: June 17, 2026 at 03:56 AM UTC
29 products affected across 2 vendorsRuntime Toolkit750-8202 Firmware750-8207 Firmware

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Severity
HIGH7.5
Exploit prediction
EPSS 3%

Description

In CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56 unauthenticated crafted invalid requests may result in several denial-of-service conditions. Running PLC programs may be stopped, memory may be leaked, or further communication clients may be blocked from accessing the PLC.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.4.7.56
Affected range stops below 2.4.7.56, so it looks safe — our inference, not a vendor statement
v < 2.4.7.56
Affected range stops below 2.4.7.56, so it looks safe — our inference, not a vendor statement
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8202 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8203 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8204 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8206 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8207 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8208 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8210 (same device)
v < fw20
Affected range stops below fw20, so it looks safe — our inference, not a vendor statement
wago-750-8211 (same device)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

CVSS

7.5HIGHCERTVDE
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-755

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