VULNERABILITY INTELLIGENCE

CVE-2021-43083

CVSS score8.8 HIGH

EPSS probability1.98%

CISA KEVNot currently listed

Published2021-12-19

Last modified2026-06-17

CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Description

Apache PLC4X - PLC4C (Only the C language implementation was effected) was vulnerable to an unsigned integer underflow flaw inside the tcp transport. Users should update to 0.9.1, which addresses this issue. However, in order to exploit this vulnerability, a user would have to actively connect to a mallicious device which could send a response with invalid content. Currently we consider the probability of this being exploited as quite minimal, however this could change in the future, especially with the industrial networks growing more and more together.

Weakness classification

security@apache.org: CWE-119
nvd@nist.gov: CWE-191

Primary references

security@apache.org — Mailing List, Third Party Advisory
security@apache.org — Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Vendor Advisory