What is CVE-2019-3951?

CVE-2019-3951 is a critical-severity vulnerability in Advantech Webaccess, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2019-12-12.

How severe is CVE-2019-3951?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2019-3951 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Advantech Webaccess

CVE-2019-3951

Advantech WebAccess before 8.4.3 allows unauthenticated remote attackers to execute arbitrary code or cause a denial of service (memory corruption) due to a stack-based buffer overflow when handling IOCTL 70533 RPC messages.

Vulnerability class: Buffer Overflow

Published 2019-12-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.036 (89.4th percentile), scored 2026-10-23.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.036 · newest: 0.036 · change: 0.000

Affected products

Advantech Webaccess
Advantech Webaccess/scada — versions 8.4.2.

Weakness classification (CWE)

Public proof-of-concept exploits

References

www.tenable.com/security/research/tra-2019-52 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-3951?: CVE-2019-3951 is a critical-severity vulnerability in Advantech Webaccess, classified under Stack-based Buffer Overflow. CVSS score: 9.8/10. Published 2019-12-12.
How severe is CVE-2019-3951?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2019-3951 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.