Authenticated code execution via unchecked username formatting
Published Mar 8, 2026 · Updated Mar 8, 2026
Stack-based buffer overflow in Tenda F453 1.0.0.3 and 3.As allows remote authenticated users to execute code via an HTTP request. In fromPptpUserAdd, opttype 1 causes sprintf to format an unbounded username into the fixed-size stack buffer s__3 without a length check. Low-privileged access to the PPTPDClient handler is required; successful exploitation can crash httpd or execute code on the device.
Summary
What happened
Stack-based buffer overflow in Tenda F453 1.0.0.3 and 3.As allows remote authenticated users to execute code via an HTTP request. In fromPptpUserAdd, opttype 1 causes sprintf to format an unbounded username into the fixed-size stack buffer s__3 without a length check. Low-privileged access to the PPTPDClient handler is required; successful exploitation can crash httpd or execute code on the device.
The record
- CVE
- CVE-2026-3729
- Published
- Mar 8, 2026
- Updated
- Mar 8, 2026
- Vendor
- Shenzhen Tenda Technology Co., Ltd.
- Product
- F453
- Classifications
- CWE-119, CWE-121, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 8, 2026CVE publishedPublication date reported by the CVE source.
- Mar 8, 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=1.0.0.3
- Affected versionversion=3.As
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
- F453 PPTPDClient proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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