Authenticated code execution via unchecked sprintf
Published May 25, 2026 · Updated May 25, 2026
Stack-based buffer overflow in Tenda F1202 1.2.0.20(408) allows remote authenticated users to execute code via a crafted delno value. The fromPPTPUserSetting handler passes the attacker-controlled delno string to sprintf without a length check, overflowing a stack buffer in httpd. Access to the router management endpoint is required; exploitation can crash the service or run code with the device process privileges.
Summary
What happened
Stack-based buffer overflow in Tenda F1202 1.2.0.20(408) allows remote authenticated users to execute code via a crafted delno value. The fromPPTPUserSetting handler passes the attacker-controlled delno string to sprintf without a length check, overflowing a stack buffer in httpd. Access to the router management endpoint is required; exploitation can crash the service or run code with the device process privileges.
The record
- CVE
- CVE-2026-9428
- Published
- May 25, 2026
- Updated
- May 25, 2026
- Vendor
- Shenzhen Tenda Technology Co., Ltd.
- Product
- F1202
- Classifications
- CWE-121, CWE-119, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 25, 2026CVE publishedPublication date reported by the CVE source.
- May 25, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=1.2.0.20(408)
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
- F1202 PPTPUserSetting delno proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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