Unauthenticated code execution via objClass command injection
Published Apr 7, 2026 · Updated Apr 7, 2026
Command injection in Topsec Internet Behavior Management System before 4.0.0.7_20210716.180815 allows remote attackers to execute commands. The Reporter toQuery.php endpoint passes the objClass parameter to a shell command without neutralizing metacharacters, enabling output redirection that writes attacker-controlled PHP into the web root. No authentication or user interaction is required, and successful exploitation runs code with the web server process privileges.
Summary
What happened
Command injection in Topsec Internet Behavior Management System before 4.0.0.7_20210716.180815 allows remote attackers to execute commands. The Reporter toQuery.php endpoint passes the objClass parameter to a shell command without neutralizing metacharacters, enabling output redirection that writes attacker-controlled PHP into the web root. No authentication or user interaction is required, and successful exploitation runs code with the web server process privileges.
The record
- CVE
- CVE-2021-4473
- Published
- Apr 7, 2026
- Updated
- Apr 7, 2026
- Vendor
- Beijing Topsec Network Security Technology Co., Ltd.
- Product
- Topsec Internet Behavior Management System
- Classifications
- CWE-78, T1190, T1505.003
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 1, 2024Exploitation reportedVulnCheck KEV listing for CVE-2021-4473
- Apr 7, 2026CVE publishedPublication date reported by the CVE source.
- Apr 7, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.0.0.7_20210716.180815
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Reporter objClass web-shell requestfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Reported exploitation
- VulnCheck KEV listing for CVE-2021-4473known exploited catalog
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo