Race Condition Vulnerability in Phoenix Contact FL SWITCH SMCS series products
Priority LOW 34CWE-362Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.
Why it matters now
EPSS 0.00678 52nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Phoenix Contact | FL SWITCH | SMCS 16TX (2700996) – 4.70; SMCS 14TX/2FX (2700997) – 4.70; SMCS 14TX/2FX-SM (2701466) – 4.70; SMCS 8GT (2891123) – 4.70; SMCS 6GT/2SFP (2891479) – 4.70; SMCS 8TX-PN (2989103) – 4.70; SMCS 4TX-PN (2989093) – 4.70; SMCS 8TX (2989226) – 4.70; SMCS 6TX/2SFP (2989323) – 4.70; SMN 6TX/2POF-PN (2700290) – 4.70; SMN 8TX-PN (2989501) – 4.70; SMN 6TX/2FX (2989543) – 4.70; SMN 6TX/2FX SM (2989556) – 4.70 | — | No fix listed | CNA |
| Phoenix Contact | FL NAT | SMN 8TX (2989365) – 4.63; SMN 8TX-M (2702443) – 4.63 | — | No fix listed | CNA |
- FL SWITCH VendorPhoenix Contact Affected SMCS 16TX (2700996) – 4.70; SMCS 14TX/2FX (2700997) – 4.70; SMCS 14TX/2FX-SM (2701466) – 4.70; SMCS 8GT (2891123) – 4.70; SMCS 6GT/2SFP (2891479) – 4.70; SMCS 8TX-PN (2989103) – 4.70; SMCS 4TX-PN (2989093) – 4.70; SMCS 8TX (2989226) – 4.70; SMCS 6TX/2SFP (2989323) – 4.70; SMN 6TX/2POF-PN (2700290) – 4.70; SMN 8TX-PN (2989501) – 4.70; SMN 6TX/2FX (2989543) – 4.70; SMN 6TX/2FX SM (2989556) – 4.70 Fixed in — No fix listed CNA
- FL NAT VendorPhoenix Contact Affected SMN 8TX (2989365) – 4.63; SMN 8TX-M (2702443) – 4.63 Fixed in — No fix listed CNA
CPE configurations NVD · 30
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_16tx_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_16tx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_14tx\/2fx_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_14tx\/2fx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_14tx\/2fx-sm_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_14tx\/2fx-sm:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_8gt_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_8gt:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_6gt\/2sfp_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_6gt\/2sfp:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_16tx_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_16tx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_14tx\/2fx_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_14tx\/2fx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_14tx\/2fx-sm_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_14tx\/2fx-sm:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_8gt_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_8gt:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_6gt\/2sfp_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_6gt\/2sfp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
Show 20 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_8tx-pn_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_8tx-pn:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_4tx-pn_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_4tx-pn:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_8tx_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_8tx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smcs_6tx\/2sfp_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smcs_6tx\/2sfp:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smn_6tx\/2pof-pn_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smn_6tx\/2pof-pn:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smn_8tx-pn_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smn_8tx-pn:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smn_6tx\/2fx_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smn_6tx\/2fx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_switch_smn_6tx\/2fx_sm_firmware:*:*:*:*:*:*:*:* | up to 4.70 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_switch_smn_6tx\/2fx_sm:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_nat_smn_8tx_firmware:*:*:*:*:*:*:*:* | up to 4.63 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_nat_smn_8tx:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
| cpe:2.3:o:phoenixcontact:fl_nat_smn_8tx-m_firmware:*:*:*:*:*:*:*:* | up to 4.63 | Vulnerable | Phoenixcontact |
| cpe:2.3:h:phoenixcontact:fl_nat_smn_8tx-m:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Phoenixcontact |
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_8tx-pn_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_8tx-pn:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_4tx-pn_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_4tx-pn:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_8tx_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_8tx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smcs_6tx\/2sfp_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smcs_6tx\/2sfp:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smn_6tx\/2pof-pn_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smn_6tx\/2pof-pn:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smn_8tx-pn_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smn_8tx-pn:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smn_6tx\/2fx_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smn_6tx\/2fx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_switch_smn_6tx\/2fx_sm_firmware:*:*:*:*:*:*:*:* Versions up to 4.70 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_switch_smn_6tx\/2fx_sm:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_nat_smn_8tx_firmware:*:*:*:*:*:*:*:* Versions up to 4.63 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_nat_smn_8tx:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
- cpe:2.3:o:phoenixcontact:fl_nat_smn_8tx-m_firmware:*:*:*:*:*:*:*:* Versions up to 4.63 Vulnerable ·Phoenixcontact
- cpe:2.3:h:phoenixcontact:fl_nat_smn_8tx-m:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Phoenixcontact
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-21005
- 2026-10-03 Alias added: GHSA-jmcx-w32h-8qj4
References
More Phoenix Contact vulnerabilities
- TI-2014-07463 Phoenix Contact Software ProConOs and MultiProg Missing Authentication for Critical Function CVSS 2.0CRITICAL 10.0
- TI-2024-17093 PHOENIX CONTACT: Remote code execution in CHARX Series CVSS 3.1CRITICAL 9.8
- TI-2022-13692 Insufficient Verification of Data Vulnerability in PHOENIX CONTACT classic line industrial controllers CVSS 3.1CRITICAL 9.8
- TI-2026-21959 Remote code execution via uploading a malicious IODD file CVSS 3.1CRITICAL 9.8
- TI-2026-21940 Authentication Bypass in _account_log CVSS 3.1CRITICAL 9.8
- TI-2023-03334 PHOENIX CONTACT: OS Command Injection in WP 6xxx Web panels CVSS 3.1CRITICAL 10.0
Sources
- CVE-2021-21005 · CVE Program
- CVE-2021-21005 · NVD
- FIRST EPSS
- GHSA-jmcx-w32h-8qj4 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences