CVE-2020-10638Network attack vector

Unauthenticated code execution via BwWebSvc IOCTL overflow

Published May 8, 2020 · Updated Aug 4, 2024

Heap-based buffer overflows in Advantech WebAccess/SCADA 8.4.4 and earlier and 9.0.0 allow remote attackers to execute arbitrary code. BwWebSvc.dll processes user-supplied data for IOCTL 0x00013c77 without validating its length, overflowing a fixed-length heap buffer. The network-accessible path requires no authentication and executes injected code with Administrator privileges.

CVSS severity9.8
Critical
EPSS probability7.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflows in Advantech WebAccess/SCADA 8.4.4 and earlier and 9.0.0 allow remote attackers to execute arbitrary code. BwWebSvc.dll processes user-supplied data for IOCTL 0x00013c77 without validating its length, overflowing a fixed-length heap buffer. The network-accessible path requires no authentication and executes injected code with Administrator privileges.

The record

CVE
CVE-2020-10638
Published
May 8, 2020
Updated
Aug 4, 2024
Vendor
Advantech
Product
WebAccess/SCADA
Classifications
CWE-122, CWE-787, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 8, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=WebAccess Node Version 8.4.4 and prior, WebAccess Node Version 9.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Advantech · WebAccess/SCADAversion=WebAccess Node Version 8.4.4 and prior, WebAccess Node Version 9.0.0

Published CVSS scores

7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8CISA ICS-CERTCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8Trend Micro Zero Day InitiativeCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
CWE-787Out-of-bounds Write
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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