CVE-2021-21003
Published: 25 June 2021
Summary
CVE-2021-21003 is a medium-severity Improper Resource Shutdown or Release (CWE-404) vulnerability in Phoenixcontact Fl Switch Smcs 16Tx Firmware. Its CVSS base score is 5.3 (Medium).
Operationally, ranked in the top 45.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2021-8412
Vulnerability details
In Phoenix Contact FL SWITCH SMCS series products in multiple versions fragmented TCP-Packets may cause a Denial of Service of Web-, SNMP- and ICMP-Echo services. The switching functionality of the device is not affected.
- 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.
Contingency plan updates incorporate proper resource shutdown and release steps, preventing attackers from leveraging incomplete cleanup during recovery scenarios.
Mandates explicit shutdown of the network connection at session conclusion, directly addressing improper resource release.
Requires proper shutdown/release procedures that include overwriting or isolating data to block unintended transfer via reused system objects.
Procedures can mandate orderly shutdown or release of resources when failures occur, preventing improper resource handling after a fault.