CVE-2021-27432
OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.95%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
OPC Foundation UA .NET Standard versions prior to 1.4.365.48 and OPC UA .NET Legacy are vulnerable to an uncontrolled recursion, which may allow an attacker to trigger a stack overflow.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.95% probability · 80th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-674
- Affected
- opcfoundation/ua-.net-legacy · opcfoundation/ua .net standard stack
- Source
- ics-cert@hq.dhs.gov
EPSS 1.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://us-cert.cisa.gov/ics/advisories/icsa-21-133-03Third Party Advisory, US Government Resource
- https://us-cert.cisa.gov/ics/advisories/icsa-21-133-03Third Party Advisory, US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.