Vulnerability · Published Apr 7, 2026 · Assigned by VulnCheck

CVE-2021-4473Tianxin Internet Behavior Management System Command Injection via toQuery.php

Critical 9.8

In plain English

A critical-severity OS command injection in Tianxin Internet Behavior Management System from Beijing Topsec Network Security Technology Co., Ltd.. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 6.3% (higher than 94% of all known vulnerabilities).

Severity (CVSS 3.1)9.8Critical

Exploit odds (30 days)6.3%top 6.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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).

Affected products (as reported)

Vendor	Product	Versions
Beijing Topsec Network Security Technology Co., Ltd.	Tianxin Internet Behavior Management System	0 – before 4.0.0.7_20210716.180815

Weakness: CWE-78 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

https://www.cnvd.org.cn/flaw/show/CNVD-2021-41972 government-resource
https://www.cnvd.org.cn/patchInfo/show/280166 patch
https://cn-sec.com/archives/4631959.html technical-description, exploit
https://avd.aliyun.com/detail?id=AVD-2021-890232 third-party-advisory
https://www.vulncheck.com/advisories/tianxin-internet-behavior-management-system-command-injection-via-toquery-php third-party-advisory