CVE-2026-75126: PLANET GS-4210-16P2S V3 Stack Buffer Overflow via dispatcher.cgi Standard Handlers
PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains multiple authenticated stack buffer overflow vulnerabilities in /cgi-bin/dispatcher.cgi. The following handlers copy attacker-controlled POST parameters into fixed-size stack buffers without length validation: webvlanmembershipeditdialogpost; webdaivlanpost; webpoealivermtippost; websyssntppost; webtoolupgradeManagerpost; webportcountersClrpost; webrmonstatisticsClrpost; webcablediagcopperpost; webaaaAuthlist handlers; webaclmgmtRulesApplypost; webaclmgmtRulesEditpost; webaclAceDelpost handlers; webaclAceAdd/Editpost handlers; webaclbindAddpost; webaclbindEditpost; websnmpv3viewaddpost; websnmpv3groupaddpost; websnmpv3communityaddpost; websnmpv3hostaddpost; websnmpnotifyv3addpost; websnmpv3useraddpost; websnmpv3remoteengineIdaddpost; webstpglobalSettingpost; webisgdbpost; webtacpluspost handlers; webdhcpoption82post; and webdhcpportoption82cidpost. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
PLANET GS-4210-16P2S V3 firmwareto a version that resolves this vulnerability.Fixed in 3.441b260626 - Compensating control
Mitigate the denial-of-service risk by restricting network access to the vulnerable web management CGI endpoint (/cgi-bin/dispatcher.cgi) so remote authenticated attackers cannot reach it (e.g., allow only trusted management IPs via firewall/ACL) until the firmware upgrade to 3.441b260626 is applied.
Event History
Frequently Asked Questions
Which systems are affected?
PLANET GS-4210-16P2S devices running firmware earlier than 3.441b260626 are affected.
What access does an attacker need?
An attacker must be able to reach the device's web management interface over the network and authenticate before sending crafted POST requests to dispatcher.cgi.
What is the practical impact of exploitation?
Successful exploitation can crash the CGI process or the web management service, causing a denial of service. The provided data does not indicate confidentiality or integrity impact.