Cyber Resilience

CVE-2021-21801

XSS in Advantech R-Seenet 2.4.12

Public PoCHigh EPSSXSS
Published
16 July 2021
Modified
21 November 2024
CVSS Score v3.1 6.1
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
EPSS Score 0.63 99.1th percentile
Risk Priority 80 floored blend · peak EPSS

Summary

CVE-2021-21801 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Advantech R-Seenet. Its CVSS base score is 6.1 (Medium).

Operationally, ranked in the top 0.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

This vulnerability is present in device_graph_page.php script, which is a part of the Advantech R-SeeNet web applications. A specially crafted URL by an attacker and visited by a victim can lead to arbitrary JavaScript code execution.

CWE(s)

Related Threats

Likely ATT&CK TechniquesAI

Techniques this vulnerability likely enables, inferred from its description, weakness type, and attributed-actor tradecraft. Confidence is per-technique.

T1189 Drive-by Compromise Initial Accessconfidence: HIGH
Specially crafted URL leading to arbitrary JavaScript execution matches Drive-by Compromise via reflected XSS.
T1059.007 JavaScript Executionconfidence: HIGH
Arbitrary JavaScript code execution directly enables JavaScript command interpreter.
inferred from description + CWE · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2023-4202Same vendor: Advantech
CVE-2023-4203Same vendor: Advantech
CVE-2023-22972Shared CWE-79
CVE-2023-4482Shared CWE-79
CVE-2023-48472Shared CWE-79
CVE-2023-4175Shared CWE-79
CVE-2023-50833Shared CWE-79
CVE-2023-30097Shared CWE-79
CVE-2023-36656Shared CWE-79
CVE-2023-2477Shared CWE-79

Affected Assets

advantech
r-seenet
2.4.12

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)

Validate
Prove the fix (OWASP ASVS)
  • V1.1.2
  • V1.3.2

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).

PR.PS-02 partial match
prevents

Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.

prevents

Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.

prevents

Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.

prevents

Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.

prevents

Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.

none

Webpage malware scanning and block-listing of known malicious sites reduce the likelihood that reflected or stored script payloads reach a user’s browser.

References