CVE-2021-34596

CVE-2021-34596 is a medium-severity vulnerability in Codesys with a CVSS 3.x base score of 6.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-824.

Key facts

Description

A crafted request may cause a read access to an uninitialized pointer in CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56, resulting in a denial-of-service condition.

Frequently asked questions

What is CVE-2021-34596?
A crafted request may cause a read access to an uninitialized pointer in CODESYS V2 Runtime Toolkit 32 Bit full and PLCWinNT prior to versions V2.4.7.56, resulting in a denial-of-service condition.
How severe is CVE-2021-34596?
CVE-2021-34596 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-34596 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-34596?
CVE-2021-34596 primarily affects Codesys. In total, 30 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-34596?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-34596 published?
CVE-2021-34596 was published on 2021-10-26 and last updated on 2026-06-17.

References

Affected products (30)

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