Summary
Multiple vulnerabilities have been identified in the FL SWITCH 2xxx, FL SWITCH TSN 23xx and FL SWITCH 59xx firmware prior to version 3.53. One of these (CVE-2026-22317) enables an attacker to execute system commands as root user on the device. Five other vulnerabilities (CVE-2026-22316, CVE-2026-22318, CVE-2026-22319, CVE-2026-22320 and CVE-2026-22321) are related to Denial of Service (DoS) attacks, which partly limit the device's functionality. Another vulnerability (CVE-2026-22322) relates to reflected cross-site scripting in the web-based management of the device. And one vulnerability (CVE-2026-22323) relates to Cross‑Site Request Forgery in the web-based management of the device. All vulnerabilities have been resolved in firmware version 3.53.
Impact
Availability, integrity, or confidentiality of the FL SWITCH 2xxx, FL SWITCH TSN 23xx and FL SWITCH 59xx can be compromised by attacks using these vulnerabilities.
Affected Product(s)
| Model no. | Product name | Affected versions |
|---|---|---|
| 2702881 | FL NAT 2008 | Firmware 3.50, Firmware <3.53 |
| 2702882 | FL NAT 2208 | Firmware 3.50, Firmware <3.53 |
| 2702981 | FL NAT 2304-2GC-2SFP | Firmware <3.53, Firmware 3.50 |
| 2702323 | FL SWITCH 2005 | Firmware <3.53, Firmware 3.50 |
| 2702324 | FL SWITCH 2008 | Firmware <3.53, Firmware 3.50 |
| 1106707 | FL SWITCH 2008F | Firmware <3.53, Firmware 3.50 |
| 2702903 | FL SWITCH 2016 | Firmware <3.53, Firmware 3.50 |
| 2702665 | FL SWITCH 2105 | Firmware <3.53, Firmware 3.50 |
| 2702666 | FL SWITCH 2108 | Firmware <3.53, Firmware 3.50 |
| 2702908 | FL SWITCH 2116 | Firmware <3.53, Firmware 3.50 |
| 2702334 | FL SWITCH 2204-2TC-2SFX | Firmware 3.50, Firmware <3.53 |
| 2702326 | FL SWITCH 2205 | Firmware 3.50, Firmware <3.53 |
| 2702330 | FL SWITCH 2206-2FX | Firmware <3.53, Firmware 3.50 |
| 2702331 | FL SWITCH 2206-2FX SM | Firmware 3.50, Firmware <3.53 |
| 2702333 | FL SWITCH 2206-2FX SM ST | Firmware 3.50, Firmware <3.53 |
| 2702332 | FL SWITCH 2206-2FX ST | Firmware <3.53, Firmware 3.50 |
| 2702969 | FL SWITCH 2206-2SFX | Firmware <3.53, Firmware 3.50 |
| 1044028 | FL SWITCH 2206-2SFX PN | Firmware <3.53, Firmware 3.50 |
| 1095628 | FL SWITCH 2206C-2FX | Firmware 3.50, Firmware <3.53 |
| 2702328 | FL SWITCH 2207-FX | Firmware 3.50, Firmware <3.53 |
| 2702329 | FL SWITCH 2207-FX SM | Firmware 3.50, Firmware <3.53 |
| 2702327 | FL SWITCH 2208 | Firmware <3.53, Firmware 3.50 |
| 1044024 | FL SWITCH 2208 PN | Firmware 3.50, Firmware <3.53 |
| 1095627 | FL SWITCH 2208C | Firmware <3.53, Firmware 3.50 |
| 2702907 | FL SWITCH 2212-2TC-2SFX | Firmware <3.53, Firmware 3.50 |
| 2702905 | FL SWITCH 2214-2FX | Firmware <3.53, Firmware 3.50 |
| 2702906 | FL SWITCH 2214-2FX SM | Firmware <3.53, Firmware 3.50 |
| 1006188 | FL SWITCH 2214-2SFX | Firmware <3.53, Firmware 3.50 |
| 1044030 | FL SWITCH 2214-2SFX PN | Firmware <3.53, Firmware 3.50 |
| 2702904 | FL SWITCH 2216 | Firmware 3.50, Firmware <3.53 |
| 1044029 | FL SWITCH 2216 PN | Firmware 3.50, Firmware <3.53 |
| 1278397 | FL SWITCH 2303-8SP1 | Firmware <3.53, Firmware 3.50 |
| 2702653 | FL SWITCH 2304-2GC-2SFP | Firmware 3.50, Firmware <3.53 |
| 2702970 | FL SWITCH 2306-2SFP | Firmware <3.53, Firmware 3.50 |
| 1009222 | FL SWITCH 2306-2SFP PN | Firmware <3.53, Firmware 3.50 |
| 2702652 | FL SWITCH 2308 | Firmware <3.53, Firmware 3.50 |
| 1009220 | FL SWITCH 2308 PN | Firmware <3.53, Firmware 3.50 |
| 2702910 | FL SWITCH 2312-2GC-2SFP | Firmware 3.50, Firmware <3.53 |
| 1006191 | FL SWITCH 2314-2SFP | Firmware 3.50, Firmware <3.53 |
| 1031683 | FL SWITCH 2314-2SFP PN | Firmware 3.50, Firmware <3.53 |
| 2702909 | FL SWITCH 2316 | Firmware <3.53, Firmware 3.50 |
| 1031673 | FL SWITCH 2316 PN | Firmware 3.50, Firmware <3.53 |
| 1184084 | FL SWITCH 2316/K1 | Firmware <3.53, Firmware 3.50 |
| 1088853 | FL SWITCH 2404-2TC-2SFX | Firmware <3.53, Firmware 3.50 |
| 1043414 | FL SWITCH 2406-2SFX | Firmware <3.53, Firmware 3.50 |
| 1089126 | FL SWITCH 2406-2SFX PN | Firmware <3.53, Firmware 3.50 |
| 1043412 | FL SWITCH 2408 | Firmware 3.50, Firmware <3.53 |
| 1089133 | FL SWITCH 2408 PN | Firmware <3.53, Firmware 3.50 |
| 1088875 | FL SWITCH 2412-2TC-2SFX | Firmware <3.53, Firmware 3.50 |
| 1043423 | FL SWITCH 2414-2SFX | Firmware 3.50, Firmware <3.53 |
| 1089139 | FL SWITCH 2414-2SFX PN | Firmware <3.53, Firmware 3.50 |
| 1043416 | FL SWITCH 2416 | Firmware <3.53, Firmware 3.50 |
| 1089150 | FL SWITCH 2416 PN | Firmware <3.53, Firmware 3.50 |
| 1088872 | FL SWITCH 2504-2GC-2SFP | Firmware <3.53, Firmware 3.50 |
| 1043491 | FL SWITCH 2506-2SFP | Firmware <3.53, Firmware 3.50 |
| 1089135 | FL SWITCH 2506-2SFP PN | Firmware 3.50, Firmware <3.53 |
| 1215329 | FL SWITCH 2506-2SFP/K1 | Firmware 3.50, Firmware <3.53 |
| 1043484 | FL SWITCH 2508 | Firmware 3.50, Firmware <3.53 |
| 1089134 | FL SWITCH 2508 PN | Firmware <3.53, Firmware 3.50 |
| 1215350 | FL SWITCH 2508/K1 | Firmware 3.50, Firmware <3.53 |
| 1088856 | FL SWITCH 2512-2GC-2SFP | Firmware 3.50, Firmware <3.53 |
| 1043499 | FL SWITCH 2514-2SFP | Firmware 3.50, Firmware <3.53 |
| 1089154 | FL SWITCH 2514-2SFP PN | Firmware 3.50, Firmware <3.53 |
| 1043496 | FL SWITCH 2516 | Firmware 3.50, Firmware <3.53 |
| 1089205 | FL SWITCH 2516 PN | Firmware <3.53, Firmware 3.50 |
| 1106500 | FL SWITCH 2608 | Firmware 3.50, Firmware <3.53 |
| 1106616 | FL SWITCH 2608 PN | Firmware <3.53, Firmware 3.50 |
| 1106615 | FL SWITCH 2708 | Firmware <3.53, Firmware 3.50 |
| 1106610 | FL SWITCH 2708 PN | Firmware <3.53, Firmware 3.50 |
| 1525942 | FL SWITCH 5916-8GC-4SFP+ | Firmware <3.53, Firmware 3.50 |
| 1525943 | FL SWITCH 5916SFP-8GC-4SFP+ | Firmware 3.50, Firmware <3.53 |
| 1525945 | FL SWITCH 5924-4GC | Firmware 3.50, Firmware <3.53 |
| 1525939 | FL SWITCH 5924-4SFP+ | Firmware 3.50, Firmware <3.53 |
| 1525944 | FL SWITCH 5924SFP-4GC | Firmware 3.50, Firmware <3.53 |
| 1232305 | FL SWITCH TSN 2312-2GC-2SFP | Firmware 3.50, Firmware <3.53 |
| 1232302 | FL SWITCH TSN 2314-2SFP | Firmware 3.50, Firmware <3.53 |
| 1232304 | FL SWITCH TSN 2316 | Firmware 3.50, Firmware <3.53 |
Vulnerabilities
Expand / Collapse allA command injection vulnerability in the device’s Root CA certificate transfer workflow allows a high-privileged attacker to send crafted HTTP POST requests that result in arbitrary command execution on the underlying Linux OS with root privileges.
A CSRF vulnerability in the Link Aggregation configuration interface allows an unauthenticated remote attacker to trick authenticated users into sending unauthorized POST requests to the device by luring them to a malicious webpage. This can silently alter the device’s configuration without the victim’s knowledge or consent. Availability impact was set to low because after a successful attack the device will automatically recover without external intervention.
A stored cross‑site scripting (XSS) vulnerability in the Link Aggregation configuration interface allows an unauthenticated remote attacker to create a trunk entry containing malicious HTML/JavaScript code. When the affected page is viewed, the injected script executes in the context of the victim’s browser, enabling unauthorized actions such as interface manipulation. The session cookie is secured by the httpOnly Flag. Therefore an attacker is not able to take over the session of an authenticated user.
A stack-based buffer overflow in the CLI's TFTP file‑transfer command handling allows a low-privileged attacker with Telnet/SSH access to trigger memory corruption by supplying unexpected or oversized filename input. Exploitation results in the corruption of the internal buffer, causing the CLI and web dashboard to become unavailable and leading to a denial of service.
A remote attacker with user privileges for the webUI can use the setting of the TFTP Filename with a POST Request to trigger a stack-based Buffer Overflow, resulting in a DoS attack.
A stack-based buffer overflow in the device's Telnet/SSH CLI login routine occurs when a unauthenticated attacker send an oversized or unexpected username input. An overflow condition crashes the thread handling the login attempt, forcing the session to close. Because other CLI sessions remain unaffected, the impact is limited to a low‑severity availability disruption.
A stack-based buffer overflow in the device's file installation workflow allows a high-privileged attacker to send oversized POST parameters that overflow a fixed-size stack buffer within an internal process, resulting in a DoS attack.
A stack-based buffer overflow vulnerability in the device's file transfer parameter workflow allows a high-privileged attacker to send oversized POST parameters, causing memory corruption in an internal process, resulting in a DoS attack.
Remediation
Phoenix Contact recommends to update to the latest 3.53 Firmware Release which fixes these vulnerabilities.
Acknowledgments
Phoenix Contact GmbH & Co. KG thanks the following parties for their efforts:
- CERT@VDE for coordination. (see https://certvde.com )
- Gabriele Quagliarella from Nozomi Networks for Reporting
Revision History
| Version | Date | Summary |
|---|---|---|
| 1.0.0 | 03/18/2026 09:00 | Initial release. |