CVE-2022-26189

published 2022-03-22

CVE-2022-26189: TOTOLINK N600R V4.3.0cu.7570_B20200620 was discovered to contain a command injection vulnerability via the langType parameter in the login interface.

Priority P2 64 critical 9.8 CVSS 3.1

AV N AC L PR N UI N S U C H I H A H

TOTOLINK N600R V4.3.0cu.7570_B20200620 was discovered to contain a command injection vulnerability via the langType parameter in the login interface.

Affected

1 ranges

Vendor	Product	Version range	Fixed in
totolink	n600r_firmware	—	—

Detection & IOCs extracted from sources · hover to see the quote

path /cgi-bin/cstecgi.cgi

snort

alert http any any -> $HOME_NET any (msg:"ET WEB_SPECIFIC_APPS TOTOLINK N600R cstecgi.cgi langType parameter Command Injection Attempt (CVE-2022-26189, CVE-2025-9935)"; flow:established,to_server; http.method; content:"POST"; http.uri; bsize:20; content:"/cgi-bin/cstecgi.cgi"; http.request_body; content:"|22|topicurl|22 3a|"; content:"|22|setting/setLanguageCfg|22|"; within:30; fast_pattern; content:"|22|langType|22 3a|"; pcre:"/^[^\x26]*?(?:(?:\x3b|%3[Bb])|(?:\x0a|%0[Aa])|(?:\x60|%60)|(?:\x7c|%7[Cc])|(?:\x24|%24))+/R"; reference:url,github.com/doudoudedi/TOTOLINK_N600R_Command_Injection/blob/main/TOTOLINK-N600R-Command-Injection.md; reference:cve,2022-26189; reference:cve,2025-9935; classtype:attempted-admin; sid:2061801; rev:1; metadata:affected_product TOTOLINK, attack_target Networking_Equipment, tls_state plaintext, created_at 2025_04_22, cve CVE_2022_26189, deployment Perimeter, deployment Internal, performance_impact Low, confidence High, signature_severity Major, tag Exploit, updated_at 2025_04_22, mitre_tactic_id TA0001, mitre_tactic_name Initial_Access, mitre_technique_id T1190, mitre_technique_name Exploit_Public_Facing_Application; target:dest_ip;)

• → Exploit targets HTTP POST requests to /cgi-bin/cstecgi.cgi with topicurl set to 'setting/setLanguageCfg' and a command injection payload in the langType parameter.
• → Command injection characters to detect in the langType parameter value include semicolon (;/%3B), newline (\n/%0A), backtick (`/%60), pipe (|/%7C), and dollar sign ($/%24). The PCRE pattern matches any of these after the langType value, excluding ampersand.
• → Traffic is expected in plaintext (no TLS); deploy detection at the network perimeter and internally.
• → The vulnerability is in the langType parameter of the login interface on TOTOLINK N600R V4.3.0cu.7570_B20200620. ↗
• → MITRE mapping: Initial Access (TA0001) via Exploit Public-Facing Application (T1190).

• · The Snort/Suricata rule (sid:2061801) also covers CVE-2025-9935 in addition to CVE-2022-26189; detections firing on this rule may relate to either CVE.
• · The URI content match uses a fixed byte size of 20 (bsize:20) for /cgi-bin/cstecgi.cgi; ensure the sensor is configured to match on the exact URI path length to avoid false negatives from path variations.

CVSS provenance

nvd v3.1 9.8 CRITICAL CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd v2.0 7.5 HIGH AV:N/AC:L/Au:N/C:P/I:P/A:P

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