CVE-2021-34595highCWE-823

CVE-2021-34595: high-severity vulnerability in CODESYS V2

CODESYS V2 runtime: out-of-bounds read or write access may result in denial-of-service

Published · Updated

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 8.1epss 0.9%
exploitation probability
0.9%top 42% of all CVEs
observed exploitation
nono source reports it
In short

A specially crafted request with invalid offsets can cause the CODESYS V2 Runtime to read or write outside its allowed memory boundaries, crashing the system or corrupting data on the affected machine.

Technical detail

Out-of-bounds memory access vulnerability in CODESYS V2 Runtime Toolkit 32 Bit and PLCWinNT (pre-V2.4.7.56) triggered by malformed requests with invalid offsets; attackers with local access can trigger denial-of-service or overwrite sensitive memory regions. The vulnerability requires crafting specific requests that bypass bounds validation during memory operations.

Summary generated and translated by AI from the official description.
A crafted request with invalid offsets may cause an out-of-bounds read or write access in CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56, resulting in a denial-of-service condition or local memory overwrite.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H
Affected products
CODESYS · CODESYS V2
Related CVEs — CODESYS V2

In the same product, most dangerous first.

CVE-2021-34586HIGHCODESYS V2 web server: crafted requests could trigger a null pointer dereference (DoS)EPSS 14.1%CVE-2021-34583HIGHCODESYS V2 web server: crafted requests could trigger a heap-based buffer overflow (DoS)EPSS 8.4%CVE-2021-34593HIGHCODESYS V2 runtime: unauthenticated invalid requests may result in denial-of-serviceEPSS 2.7%CVE-2021-34584CRITICALCODESYS V2 web server: crafted requests could trigger a buffer over-read (DoS)EPSS 1.1%CVE-2021-34585HIGHCODESYS V2 web server: crafted requests could trigger a pointer dereference with an invalid address (DoS)EPSS 0.9%CVE-2021-34596MEDIUMCODESYS V2 runtime: Access of Uninitialized Pointer may result in denial-of-serviceEPSS 0.9%
References
https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=16878&token=e5644ec405590e66aefa62304cb8632df9fc9e9c&download=