What’s Vulnerable › Vulnerabilities

CVE-2021-33540: Phoenix Contact: Undocumented FTP acces in certain AXL F BK and IL BK devices

• Severity: high (CVSS 7.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-06-25 · updated 2026-06-17
• Weakness: CWE-798

Description

In certain devices of the Phoenix Contact AXL F BK and IL BK product families an undocumented password protected FTP access to the root directory exists.

Affected products

• Phoenixcontact Axl F Bk Eip Ef Firmware: before 1.30 — fixed in 1.30
• Phoenixcontact Axl F Bk Eip Firmware: before 1.30 — fixed in 1.30
• Phoenixcontact Axl F Bk Eth Firmware: before 1.30 — fixed in 1.30
• Phoenixcontact Axl F Bk Eth Net2 Firmware: all versions
• Phoenixcontact Axl F Bk Eth Xc Firmware: before 1.30 — fixed in 1.30
• Phoenixcontact Axl F Bk Pn Firmware: all versions
• Phoenixcontact Axl F Bk Pn Tps Firmware: before 1.30 — fixed in 1.30
• Phoenixcontact Axl F Bk Pn Tps Xc Firmware: before 1.30 — fixed in 1.30
• Phoenixcontact Axl F Bk Pn Xc Firmware: all versions
• Phoenixcontact Axl F Bk S35 Firmware: before 1.40 — fixed in 1.40
• Phoenixcontact Axl F Bk Sas Firmware: all versions
• Phoenixcontact Il Eip Bk Di8 Do4 2Tx-Pac Firmware: all versions
• Phoenixcontact Il Eth Bk Di8 Do4 2Tx-Pac Firmware: all versions
• Phoenixcontact Il Eth Bk Di8 Do4 2Tx-Xc-Pac Firmware: all versions
• Phoenixcontact Il Pn Bk-Pac Firmware: all versions
• Phoenixcontact Il Pn Bk Di8 Do4 2Scrj-Pac Firmware: all versions
• Phoenixcontact Il Pn Bk Di8 Do4 2Tx-Pac Firmware: all versions
• Phoenixcontact Il S3 Bk Di8 Do4 2Tx-Pac Firmware: all versions

How to fix

Upgrade to a fixed version: Phoenixcontact Axl F Bk Eip Ef Firmware 1.30; Phoenixcontact Axl F Bk Eip Firmware 1.30; Phoenixcontact Axl F Bk Eth Firmware 1.30; Phoenixcontact Axl F Bk Eth Xc Firmware 1.30; Phoenixcontact Axl F Bk Pn Tps Firmware 1.30; Phoenixcontact Axl F Bk Pn Tps Xc Firmware 1.30; Phoenixcontact Axl F Bk S35 Firmware 1.40. Check the vendor advisory for mitigations.

References

• https://cert.vde.com/en-us/advisories/vde-2021-021
• https://cert.vde.com/en-us/advisories/vde-2021-021

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