PLANET GS-4210-16P2S CVE-2026-75125

Exploitation requires an authenticated session with high-privilege (administrator-level) credentials to the device's web management interface, confirmed by PR:H in the CVSS 4.0 vector - unauthenticated or low-privilege users cannot trigger this condition. The specific trigger is a POST request to the web_poe_alive_rmtip_post handler within /cgi-bin/dispatcher.cgi with the rmtIP parameter omitted from the request body. No special network positioning beyond IP reachability to the management interface is required (AV:N, AC:L, AT:N). Exploitation is bounded by the credential requirement and the fact that impact is limited to the web management plane only - switch forwarding operations are unaffected. Deployments that restrict web management access to a dedicated management VLAN or management-only IP ACL are substantially protected even without the firmware patch applied.

The CVSS 4.0 score of 6.9 accurately captures the risk profile: network-accessible (AV:N) and low complexity (AC:L), but gated behind high-privilege authentication (PR:H) with impact confined entirely to availability (VA:H) - no confidentiality or integrity impact in either the vulnerable system or subsequent systems (SC:N/SI:N/SA:N). The requirement for high-privilege credentials is the primary mitigating factor; unauthenticated or low-privilege users cannot trigger this condition. EPSS data was not provided in the source intelligence, so probability-of-exploitation-in-30-days cannot be quantified from that signal. The vulnerability is not listed in the CISA KEV catalog, and no public proof-of-concept code has been identified. In well-configured deployments the web management interface should be isolated to a dedicated management VLAN and unreachable from untrusted segments, which dramatically reduces real-world exposure. The simplicity of the trigger means accidental or deliberate disruption by any authenticated administrator is plausible without specialized knowledge. Overall, this is a moderate-severity operational risk, not a high-priority exploitation priority absent credential compromise.

An attacker who has obtained or already holds valid administrative credentials to the PLANET GS-4210-16P2S web interface submits a POST request to /cgi-bin/dispatcher.cgi targeting the web_poe_alive_rmtip_post action while deliberately omitting the rmtIP parameter from the request body. The handler dereferences the absent parameter as a null pointer, causing the CGI process to fault immediately and crash. The web management interface becomes unresponsive, preventing legitimate administrators from accessing or reconfiguring the switch until the process recovers or the device is power-cycled.