CVE-2026-77218
MediumCVSS 4.9Exploitation Probability (EPSS)
Low risk34th percentile - higher than 34% of all known CVEs
Summary
PLANET GS-4210-16P2S firmware before 3.441b260626 contains authenticated stack buffer overflow vulnerabilities in /cgi-bin/dispatcher.cgi. The web_login_first_post handler copies the usrPass POST parameter into a fixed-size stack buffer without length validation, the web_sys_enablePasswd_post handler copies the enbPass POST parameter into a fixed-size stack buffer without length validation, and the web_sys_localUser_post handler copies the usrName and usrPass POST parameters into fixed-size stack buffers without length validation. A remote authenticated attacker can send a crafted request to crash the CGI process or web management service, resulting in denial of service.
Risk Assessment
The risk includes the possibility of remotely crashing the device management service, potentially leading to network disruptions and inability to manage the device. The attack requires authentication but can be used to destabilize infrastructure.
Recommendation
It is recommended to upgrade PLANET GS-4210-16P2S firmware to version 3.441b260626 or later, which contains fixes. Also, restrict access to the management interface to trusted networks and monitor logs for suspicious requests.
Other vulnerabilities in PLANET GS-4210-16P2S
See all- CVE-2026-77217Medium
PLANET GS-4210-16P2S firmware before 3.441b260626 contains authenticated stack buffer overflow and null pointer dereference vulnerabilities in /cgi-bin/dispatcher.cgi. The web_radiusSrv*_post family of handlers copies the radKey, radKey_0, radDftParamKey, radName, and radIp POST parameters into fixed-size stack buffers without length validation, and additionally dereferences radName and radIp without verifying their presence in the request. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.
- CVE-2026-75126Medium
PLANET GS-4210-16P2S 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: web_vlan_membership_edit_dialog_post; web_dai_vlan_post; web_poe_alive_rmtip_post; web_sys_sntp_post; web_tool_upgradeManager_post; web_port_countersClr_post; web_rmon_statisticsClr_post; web_cablediag_copper_post; web_aaa_*Authlist* handlers; web_acl_mgmt_Rules_Apply_post; web_acl_mgmt_Rules_Edit_post; web_acl_*AceDel_post handlers; web_acl_*AceAdd/Edit_post handlers; web_acl_bindAdd_post; web_acl_bindEdit_post; web_snmp_v3view_add_post; web_snmp_v3group_add_post; web_snmp_v3community_add_post; web_snmp_v3host_add_post; web_snmp_notifyv3_add_post; web_snmp_v3user_add_post; web_snmpv3_remote_engineId_add_post; web_stp_globalSetting_post; web_isg_db_post; web_tacplus*_post handlers; web_dhcp_option82_post; and web_dhcp_port_option82_cid_post. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.
- CVE-2026-75125Medium
PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated null pointer dereference vulnerability in /cgi-bin/dispatcher.cgi. The web_poe_alive_rmtip_post handler dereferences the rmtIP parameter without verifying its presence. A remote authenticated attacker can send a crafted request omitting the rmtIP parameter to cause the CGI process to dereference a null pointer and crash, resulting in denial of service of the web management interface.
- CVE-2026-75124High
PLANET GS-4210-16P2S firmware before 3.441b260626 contains a pre-authentication memory corruption vulnerability in the web management interface where the _readHttpParam function copies an oversized HTTP query string without guaranteeing NUL termination, allowing parse_query_string to process attacker-controlled data into a fixed-size stack buffer. An unauthenticated remote attacker can send an oversized GET request to dispatcher.cgi to cause denial of service of the web management interface and potentially trigger memory corruption.
- CVE-2026-75123High
PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated OS command injection vulnerability in /cgi-bin/dispatcher.cgi. The web_smtp_test_post handler incorporates a caller-supplied SMTP server value directly into a shell command without sanitization. A remote attacker with administrator web credentials can send a crafted SMTP server value to execute arbitrary operating-system commands on the device.
- CVE-2026-75122High
PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated OS command injection vulnerability in /cgi-bin/httpuploadcert.cgi. The certificate password field in a certificate upload request is incorporated into a shell command without sanitization of shell metacharacters. A remote attacker with administrator web credentials can submit a crafted certificate upload request to execute arbitrary operating-system commands on the device.
- CVE-2026-75121High
PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated OS command injection vulnerability in /cgi-bin/dispatcher.cgi. The web_vlan_membership_edit_dialog_post handler incorporates the memberTags POST parameter into a shell command without sanitization. A remote authenticated attacker can send a crafted memberTags value to execute arbitrary operating-system commands on the device.
Original NVD description (English source)
PLANET GS-4210-16P2S firmware before 3.441b260626 contains authenticated stack buffer overflow vulnerabilities in /cgi-bin/dispatcher.cgi. The web_login_first_post handler copies the usrPass POST parameter into a fixed-size stack buffer without length validation, the web_sys_enablePasswd_post handler copies the enbPass POST parameter into a fixed-size stack buffer without length validation, and the web_sys_localUser_post handler copies the usrName and usrPass POST parameters into fixed-size stack buffers without length validation. A remote authenticated attacker can send a crafted request to crash the CGI process or web management service, resulting in denial of service.