CVE-2021-21004
Published: 25 June 2021
Summary
CVE-2021-21004 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Phoenixcontact Fl Switch Smcs 16Tx Firmware. Its CVSS base score is 7.4 (High).
Operationally, ranked at the 47.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-8413
Vulnerability details
In Phoenix Contact FL SWITCH SMCS series products in multiple versions an attacker may insert malicious code via LLDP frames into the web-based management which could then be executed by the client.
- CWE(s)
Related Threats
No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.
Affected Assets
Mitigating Controls
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.
Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.
Validates web inputs to reject script-related content that could produce XSS.
Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.