PT-2026-30817 · Beijing Topsec Network Security Technology Co. · Tianxin Internet Behavior Management System

Published 2026-04-07 · Updated 2026-04-07 · CVE-2021-4473

Mitre

CVSS v3.1

9.8

Critical

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

Tianxin Internet Behavior Management System contains a command injection vulnerability in the Reporter component endpoint that allows unauthenticated attackers to execute arbitrary commands by supplying a crafted objClass parameter containing shell metacharacters and output redirection. Attackers can exploit this vulnerability to write malicious PHP files into the web root and achieve remote code execution with the privileges of the web server process. This vulnerability has been fixed in version NACFirmware 4.0.0.7 20210716.180815 topsec 0 basic.bin. Exploitation evidence was first observed by the Shadowserver Foundation on 2024-06-01 (UTC).

Exploit

Fix

OS Command Injection

Weakness Enumeration

CWE-78

Related Identifiers

CVE-2021-4473

Affected Products

Tianxin Internet Behavior Management System

References · 6

• 🔥 https://cn-sec.com/archives/4631959.html · Exploit
• https://cnvd.org.cn/patchInfo/show/280166 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2021-4473 · Security Note
• https://avd.aliyun.com/detail?id=AVD-2021-890232 · Note
• https://cnvd.org.cn/flaw/show/CNVD-2021-41972 · Note
• https://vulncheck.com/advisories/tianxin-internet-behavior-management-system-command-injection-via-toquery-php · Note