Unauthenticated command execution via unsanitized resetFlags
Published Apr 6, 2026 · Updated Apr 6, 2026
OS command injection in TOTOLINK A7100RU 7.4cu.2313_b20191024 allows remote attackers to execute arbitrary commands via a crafted CGI request. The sub_42356C handler inserts resetFlags into a command buffer with snprintf, after which CsteSystem passes the resulting command to execv without neutralizing command syntax. Network access to the router's CGI service is sufficient under the CNA assessment, and successful exploitation runs commands with the CGI process's privileges.
Summary
What happened
OS command injection in TOTOLINK A7100RU 7.4cu.2313_b20191024 allows remote attackers to execute arbitrary commands via a crafted CGI request. The sub_42356C handler inserts resetFlags into a command buffer with snprintf, after which CsteSystem passes the resulting command to execv without neutralizing command syntax. Network access to the router's CGI service is sufficient under the CNA assessment, and successful exploitation runs commands with the CGI process's privileges.
The record
- CVE
- CVE-2026-5677
- Published
- Apr 6, 2026
- Updated
- Apr 6, 2026
- Vendor
- TOTOLINK
- Product
- A7100RU
- Classifications
- CWE-77, CWE-78, T1059.004, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 6, 2026CVE publishedPublication date reported by the CVE source.
- Apr 6, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=7.4cu.2313_b20191024
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
- A7100RU resetFlags command-injection proof of conceptfunctional · demonstrated
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Technologies
Your stack
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Your stack
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