Unauthenticated root command execution via infosrvd packet
Published Aug 27, 2026 · Updated Aug 27, 2026
Command injection in Zbtlink router firmware allows remote attackers to execute arbitrary commands as root through the infosrvd UDP service. The command handler appends an unfiltered packet payload to /etc/exec/cmd and passes the result to system, so a semicolon escapes the fixed prefix. Network reachability to UDP port 9992 is sufficient because a hardcoded checksum salt and an all-zero MAC field defeat both acceptance checks.
Summary
What happened
Command injection in Zbtlink router firmware allows remote attackers to execute arbitrary commands as root through the infosrvd UDP service. The command handler appends an unfiltered packet payload to /etc/exec/cmd and passes the result to system, so a semicolon escapes the fixed prefix. Network reachability to UDP port 9992 is sufficient because a hardcoded checksum salt and an all-zero MAC field defeat both acceptance checks.
The record
- CVE
- CVE-2026-74233
- Published
- Aug 27, 2026
- Updated
- Aug 27, 2026
- Vendor
- Shenzhen Zhibotong Electronics Co., Ltd.
- Product
- WE5926
- Classifications
- CWE-78, CWE-321, T1059.004, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 27, 2026CVE publishedPublication date reported by the CVE source.
- Aug 27, 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=19.1101
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
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Weakness, pattern, technique
Public exploit references
- DARKLANTERN command-packet procedurefunctional · demonstrated
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Reported exploitation
- VulnCheck KEV listingknown exploited catalog
Technologies
Your stack
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Your stack
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