Unauthenticated command execution via unsanitized hour parameter
Published Apr 23, 2026 · Updated Apr 23, 2026
Command injection in TOTOLINK A3300R firmware 17.0.0cu.557_B20221024 allows remote attackers to execute arbitrary commands via an HTTP request. The cstecgi.cgi handler passes the unvalidated hour value through Uci_Set_Str and sprintf into CsteSystem, which wraps it as a command and invokes execv. Network access to the router web interface is sufficient, and successful injection executes attacker-selected commands through the firmware command path.
Summary
What happened
Command injection in TOTOLINK A3300R firmware 17.0.0cu.557_B20221024 allows remote attackers to execute arbitrary commands via an HTTP request. The cstecgi.cgi handler passes the unvalidated hour value through Uci_Set_Str and sprintf into CsteSystem, which wraps it as a command and invokes execv. Network access to the router web interface is sufficient, and successful injection executes attacker-selected commands through the firmware command path.
The record
- CVE
- CVE-2026-31166
- Published
- Apr 23, 2026
- Updated
- Apr 23, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-77, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 23, 2026CVE publishedPublication date reported by the CVE source.
- Apr 23, 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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What is affected?
Affected products and versions are unavailable in this record.
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
- A3300R hour command-injection proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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