Authenticated code execution via unchecked extChannel stack copy
Published Jul 10, 2025 · Updated Jul 11, 2025
Stack-based buffer overflow in Tenda O3V2 1.0.0.12(3880) allows remote authenticated users to crash the device via extChannel. The formWifiBasicSet handler copies the extChannel POST parameter into a fixed-size stack buffer without checking its length, overwriting the return address. Access requires an administrative session cookie; the published proof crashes httpd, while return-address control supports arbitrary code execution.
Summary
What happened
Stack-based buffer overflow in Tenda O3V2 1.0.0.12(3880) allows remote authenticated users to crash the device via extChannel. The formWifiBasicSet handler copies the extChannel POST parameter into a fixed-size stack buffer without checking its length, overwriting the return address. Access requires an administrative session cookie; the published proof crashes httpd, while return-address control supports arbitrary code execution.
The record
- CVE
- CVE-2025-7420
- Published
- Jul 10, 2025
- Updated
- Jul 11, 2025
- Vendor
- Shenzhen Tenda Technology Co., Ltd.
- Product
- O3
- Classifications
- CWE-121, CWE-119, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 10, 2025CVE publishedPublication date reported by the CVE source.
- Jul 11, 2025Record 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=1.0.0.12(3880)
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
- Tenda O3V2 extChannel crash proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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