CVE-2025-9813: A vulnerability was identified in Tenda CH22 1.0.0.1. This issue affects the function formSetSambaConf of the file /goform/SetSambaConf. The manipulation of…

PriorityP263high8.8CVSS 3.1

AVNACLPRLUINSUCHIHAH

EPSS

0.78%

51.8th percentile

A vulnerability was identified in Tenda CH22 1.0.0.1. This issue affects the function formSetSambaConf of the file /goform/SetSambaConf. The manipulation of the argument samba_userNameSda leads to buffer overflow. It is possible to initiate the attack remotely. The exploit is publicly available and might be used.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
tenda	ch22	—	—
tenda	ch22_firmware	—	—

Detection & IOCsextracted from sources · hover to see the quote

path/goform/SetSambaConf↗

snort

alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS Tenda SetSambaConf samba_userNameSda Parameter Buffer Overflow Attempt (CVE-2025-9813)"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:20; content:"/goform/SetSambaConf"; fast_pattern; http.request_body; content:"samba_userNameSda|3d|"; pcre:"/^[^&]{100,}(?:&|$)/R"; reference:url,vuldb.com/?id.322140; reference:cve,2025-9813; classtype:web-application-attack; sid:2065986; rev:1; metadata:affected_product Tenda, attack_target Networking_Equipment, tls_state plaintext, created_at 2025_12_02, cve CVE_2025_9813, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2025_12_02, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)

→Attack is delivered via HTTP POST to the URI /goform/SetSambaConf; look for POST requests to this endpoint on Tenda CH22 devices.
→The vulnerable parameter is samba_userNameSda in the POST body; a value exceeding 100 characters (with no intervening '&') is indicative of a buffer overflow attempt.
→The exploit is publicly available and the attack can be initiated remotely; prioritize perimeter and internal network monitoring for this signature.
→Traffic is expected in plaintext (not TLS); focus detection on unencrypted HTTP traffic to internal networking equipment.
→MITRE ATT&CK mapping: Initial Access (TA0001) via Exploit Public-Facing Application (T1190).

·The Snort/Suricata rule targets $HOME_NET as the destination; ensure HOME_NET is correctly scoped to include Tenda CH22 device IP ranges for effective detection.
·The URI match uses a fixed buffer size of 20 bytes (bsize:20); this is an exact-length match on '/goform/SetSambaConf' and will not match if the URI contains additional path components.
·The overflow threshold in the PCRE is set at 100 or more non-'&' characters for the samba_userNameSda value; legitimate long 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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