CVE-2021-27434 is an uncontrolled recursion vulnerability affecting Unified Automation .NET based OPC UA Client/Server SDK Bundle versions V3.0.7 and prior, specifically within .NET Framework versions 4.5, 4.0, and 3.5. This flaw allows an unauthenticated attacker to trigger a stack overflow, leading to a denial of service. Rated High with a CVSS score of 7.5, the attack is network-based and low complexity. There is no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or inclusion in CISA's KEV catalog, though it has received some community discussion and media coverage.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
<= 3.0.7CPE matchmatch criteria | cpe:2.3:a:unified-automation:.net_based_opc_ua_client\/server_sdk:*:*:*:*:*:*:*:* |
CVSS version used by this source: 3.1
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.
Remediation records are not available for this CVE.