cbcvebase.
CVE-2023-43238
published 2023-09-21

CVE-2023-43238: D-Link DIR-816 A2 v1.10CNB05 was discovered to contain a stack overflow via parameter nvmacaddr in form2Dhcpip.cgi.

PriorityP356critical9.8CVSS 3.1
AVNACLPRNUINSUCHIHAH
EPSS
1.04%
59.9th percentile
D-Link DIR-816 A2 v1.10CNB05 was discovered to contain a stack overflow via parameter nvmacaddr in form2Dhcpip.cgi.

Affected

1 ranges
VendorProductVersion rangeFixed in
dlinkdir-816_a2_firmware——

Detection & IOCsextracted from sources · hover to see the quote

url/goform/form2Dhcpip.cgi
path/goform/form2Dhcpip.cgi↗
snort
alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS D-Link form2Dhcpip.cgi nvmacaddr Parameter Buffer Overflow Attempt (CVE-2023-43238)"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:23; content:"/goform/form2Dhcpip.cgi"; fast_pattern; http.request_body; content:"nvmacaddr|3d|"; pcre:"/^[^&]{100,}(?:&|$)/R"; reference:url,github.com/peris-navince/founded-0-days/blob/main/Dlink/816/form2Dhcpip_cgi/1.md; reference:cve,2023-43238; classtype:web-application-attack; sid:2065137; rev:1; metadata:affected_product D_Link, attack_target Networking_Equipment, tls_state plaintext, created_at 2025_10_10, cve CVE_2023_43238, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_10_10, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)
  • →Exploit arrives as an HTTP POST request to the exact URI /goform/form2Dhcpip.cgi (URI length is exactly 23 bytes); match on HTTP method POST combined with this URI.
  • →The overflow is triggered via the nvmacaddr POST body parameter; look for 'nvmacaddr=' (URL-encoded as nvmacaddr|3d|) followed by a value of 100 or more characters before an '&' or end-of-body.
  • →Traffic is expected in plaintext (not TLS); deploy detection at the network perimeter and internally on segments hosting D-Link DIR-816 A2 devices.
  • →Reference PoC/exploit details are publicly available at github.com/peris-navince/founded-0-days/blob/main/Dlink/816/form2Dhcpip_cgi/1.md — use for payload pattern research.
  • ·Affected product is specifically D-Link DIR-816 A2 firmware version v1.10CNB05; the vulnerability and detection rule are scoped to this exact hardware/firmware combination. ↗
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