cbcvebase.
CVE-2025-9938
published 2025-09-04

CVE-2025-9938: A weakness has been identified in D-Link DI-8400 16.07.26A1. The affected element is the function yyxz_dlink_asp of the file /yyxz.asp. This manipulation of…

PriorityP266high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
EPSS
1.40%
69.2th percentile
A weakness has been identified in D-Link DI-8400 16.07.26A1. The affected element is the function yyxz_dlink_asp of the file /yyxz.asp. This manipulation of the argument ID causes stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be exploited.

Affected

2 ranges
VendorProductVersion rangeFixed in
d-linkdi-8400——
dlinkdi-8400_firmware——

Detection & IOCsextracted from sources · hover to see the quote

path/yyxz.asp↗
snort
alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS D-Link yyxz.asp id Parameter Buffer Overflow Attempt (CVE-2025-9938)"; flow:established,to_server; http.method; content:"GET"; http.uri; content:"/yyxz.asp|3f|"; startswith; fast_pattern; content:"id|3d|"; distance:0; pcre:"/^[^&]{100,}(?:&|$)/R"; reference:url,github.com/ZZ2266/.github.io/tree/main/Dlink/DI-8400/yyxz.asp; reference:cve,2025-9938; classtype:web-application-attack; sid:2064541; rev:1; metadata:affected_product D_Link, attack_target Networking_Equipment, tls_state plaintext, created_at 2025_09_11, cve CVE_2025_9938, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_09_11, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)
  • →Look for HTTP GET requests targeting /yyxz.asp with an 'id' parameter value exceeding 100 characters, indicative of a stack-based buffer overflow attempt against D-Link DI-8400.
  • →The attack is remotely initiated over plaintext HTTP targeting the device's web interface; monitor perimeter and internal network traffic for exploitation attempts.
  • →Public exploit code is available at the referenced GitHub repository; threat hunting should include correlation against known exploit PoC traffic patterns.
  • →MITRE mapping: Initial Access (TA0001) via Exploit Public-Facing Application (T1190); prioritize detection at network perimeter and internal segments hosting D-Link DI-8400 devices.
  • ·The Snort/Suricata rule (sid:2064541) is designed for plaintext HTTP only; encrypted HTTPS traffic to the device will not be detected by this signature.
  • ·The PCRE threshold of 100+ characters for the 'id' parameter is the detection trigger; legitimate requests with long 'id' values (if any) could produce false positives.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvdv4.07.4HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
nvdv2.09.0CRITICALAV:N/AC:L/Au:S/C:C/I:C/A:C
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