Unauthenticated command execution via unsanitized timezone input
Published Apr 27, 2026 · Updated Apr 27, 2026
OS command injection in TOTOLINK A8000RU 7.1cu.643_b20200521 allows remote attackers to execute arbitrary OS commands via HTTP. The setNtpCfg handler in /cgi-bin/cstecgi.cgi inserts the untrusted tz value into a command string that CsteSystem ultimately executes with execv(). Unauthenticated access to the router management interface is sufficient; successful exploitation grants command execution on the appliance.
Summary
What happened
OS command injection in TOTOLINK A8000RU 7.1cu.643_b20200521 allows remote attackers to execute arbitrary OS commands via HTTP. The setNtpCfg handler in /cgi-bin/cstecgi.cgi inserts the untrusted tz value into a command string that CsteSystem ultimately executes with execv(). Unauthenticated access to the router management interface is sufficient; successful exploitation grants command execution on the appliance.
The record
- CVE
- CVE-2026-7138
- Published
- Apr 27, 2026
- Updated
- Apr 27, 2026
- Vendor
- TOTOLINK
- Product
- A8000RU
- Classifications
- CWE-77, T1059, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 27, 2026CVE publishedPublication date reported by the CVE source.
- Apr 27, 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=7.1cu.643_b20200521
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
- A8000RU setNtpCfg command-injection proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
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