CVE-2023-2866: If an attacker can trick an authenticated user into loading a maliciously crafted .zip file onto Advantech We

Routine

HIGH 7.3DOWNGRADE

CVE-2023-2866 is a high-severity flaw (CVSS 7.3) affecting webaccess. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

If an attacker can trick an authenticated user into loading a maliciously crafted .zip file onto Advantech WebAccess version 8.4.5, a web shell could be used to give the attacker full control of the SCADA server.

Why this priority

High severity

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	7.3 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	Required
EPSS exploit chance	0.1% (top 96%)
CISA exploited list	No
Weakness	CWE-351, CWE-345
Published	2023-06-07
Last modified	2026-06-17

Publisher (CNA): ICS-CERT · Vendor: advantech

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-06-07 21:15 UTCPublished CVE record published
2026-06-17 05:53 UTCUpdated Record last modified

advantech webaccess DOWNGRADE

Affected: 8.4.5

Fixed in: no fixed release known

Safe to downgrade to: a release before 8.4.5

1. Check installed version

apt-cache policy webaccess || rpm -q webaccess || webaccess --version

2. No fixed release: DOWNGRADE to a release before 8.4.5 (Debian / Ubuntu)

apt-cache madison webaccess sudo apt install webaccess=<VERSION_BEFORE_8.4.5> sudo apt-mark hold webaccess

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list webaccess sudo dnf downgrade webaccess-<VERSION_BEFORE_8.4.5> sudo dnf versionlock add webaccess

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-2866?

webaccess: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-2866 being exploited?

CVE-2023-2866 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-2866 affect?

CVE-2023-2866 affects webaccess. Severity is high (CVSS 7.3). If an attacker can trick an authenticated user into loading a maliciously crafted .zip file onto Advantech WebAccess version 8.4.5, a web shell could be used to give the attacker full control of the SCADA server.

How urgent is CVE-2023-2866?

Priority 26/100. High severity

Software pages

Advantech vulnerabilities

Related CVEs

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CVE-2021-38408 CRITICAL 9.8 UPGRADE A stack-based buffer overflow vulnerability in Advantech WebAccess Versions 9.02 and prior caused by a lack of
CVE-2021-38389 CRITICAL 9.8 UPGRADE Advantech WebAccess versions 9.02 and prior are vulnerable to a stack-based buffer overflow, which may allow a
CVE-2021-34540 MEDIUM 6.1 DOWNGRADE Advantech WebAccess 8.4.2 and 8.4.4 allows XSS via the username column of the bwRoot.asp page of WADashboard.
CVE-2021-33023 CRITICAL 9.8 UPGRADE Advantech WebAccess versions 9.02 and prior are vulnerable to a heap-based buffer overflow, which may allow an

References

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