CVE-2021-22676
No exploitation reported by the sources we read.
- Published2021-08-10
- Fixed in9.0.1 · 8.4.5
- WeaknessCWE-79
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
UserExcelOut.asp within WebAccess/SCADA is vulnerable to cross-site scripting (XSS), which could allow an attacker to send malicious JavaScript code. This could result in hijacking of cookie/session tokens, redirection to a malicious webpage, and unintended browser action on the WebAccess/SCADA (WebAccess/SCADA versions prior to 8.4.5, WebAccess/SCADA versions prior to 9.0.1).
Timeline
dates in UTC- 2021-08-1015:15CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2021-22676?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2021-22676?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 9.0 | ≥ 9.0, < 9.0.1 | 9.0.1 | NVD |
| 8.4 | < 8.4.5 | 8.4.5 | NVD |
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Vendor advisories
Advantech WebAccess SCADA
WebAccess/SCADA: versions prior to 9.0.1 · WebAccess/SCADA: versions prior to 8.4.5
Fix
- Update Advantech webaccess\/scada to 9.0.1 · 8.4.5
- Mitigation from the vendor CISA ICSA-21-217-04 · 2 productsAdvantech recommends users running version 8 of the software to update to Version 8.4.5
- Mitigation from the vendor CISA ICSA-21-217-04 · 2 productsAdvantech recommends users running version 9 of the software to update to Version 9.0.1
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.16.1read 2026-10-23
- NVDCVSS 2.04.3read 2026-10-23
- CNAweakness (CWE)CWE-79read 2026-10-23
- NVDweakness (CWE)CWE-79read 2026-10-23
- FIRST EPSSEPSS score0.6 %2026-10-22
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Published
- 2021-08-10
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2021-22676?
Is CVE-2021-22676 actively exploited?
What is the CVSS score for CVE-2021-22676?
Hear about the next vulnerability in your software
Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».
No credit card required · No monthly cap on website lookups · 250 API requests/month
Go further
- Following what attackers exploit right now? The CISA KEV additions of the month, with their patch deadlines.
- Running this software? Vulnerability monitoring alerts you to new vulnerabilities in your products.
Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.