Authenticated code execution via unchecked ethConv copy
Published Aug 10, 2025 · Updated Aug 12, 2025
Stack-based buffer overflow in six Linksys range extenders through 20250801 allows remote authenticated users to execute arbitrary code. The setOpMode handler stores an unchecked ethConv value with nvram_bufset, and setWan later copies it into a stack buffer, overwriting the return address. Access to a web administration session is required; the published proof of concept persistently crashes the device, while return-address control supports code execution.
Summary
What happened
Stack-based buffer overflow in six Linksys range extenders through 20250801 allows remote authenticated users to execute arbitrary code. The setOpMode handler stores an unchecked ethConv value with nvram_bufset, and setWan later copies it into a stack buffer, overwriting the return address. Access to a web administration session is required; the published proof of concept persistently crashes the device, while return-address control supports code execution.
The record
- CVE
- CVE-2025-8816
- Published
- Aug 10, 2025
- Updated
- Aug 12, 2025
- Vendor
- Linksys
- Product
- RE6250
- Classifications
- CWE-121, CWE-119, T1210
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 10, 2025CVE publishedPublication date reported by the CVE source.
- Aug 12, 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?
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- Affected versionversion=20250801
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
- setOpMode ethConv proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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