PT-2021-3339 · 3S Smart Software Solutions · Codesys V2 Web-Server

Anton Dorfman + 1 · CVE-2021-30191 · Published 2021-05-25 · Updated 2025-08-15

Positive Technologies (AI Summary)

CVSS v2.0

7.8

High

Base vector

AV:N/AC:L/Au:N/C:N/I:N/A:C

Name of the Vulnerable Software and Affected Versions CODESYS V2 Web-Server versions prior to 1.1.9.20

Description The issue is caused by a buffer copy without checking the size of the input, which can lead to a buffer overflow on the stack. This can allow a remote attacker to cause a denial of service.

Recommendations For CODESYS V2 Web-Server versions prior to 1.1.9.20, update to version 1.1.9.20 or later to resolve the issue. As a temporary workaround, consider restricting access to the web server to minimize the risk of exploitation.

Fix

Buffer Overflow

Weakness Enumeration

CWE-120

Related Identifiers

BDU:2021-03148

CVE-2021-30191

Affected Products

Codesys V2 Web-Server

References · 8

• https://nvd.nist.gov/vuln/detail/CVE-2021-30191 · Security Note
• https://bdu.fstec.ru/vul/2021-03148 · Security Note
• https://customers.codesys.com/index.php · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-30191 · Vendor Advisory
• https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=14726&token=553da5d11234bbe1ceed59969d419a71bb8c8747&download= · Vendor Advisory
• https://t.me/cvenotify/15069 · Telegram Post
• https://xakep.ru/2021/06/04/codesys-flaws · Note
• https://t.me/cveNotify/132544 · Telegram Post