Router crash via oversized service_type parameter
Published Jul 25, 2025 · Updated Jul 25, 2025
Stack-based buffer overflow in TOTOLINK A702R 4.0.0-B20230721.1521 allows remote authenticated users to crash the router. The /boafrm/formPortFw HTTP POST handler copies an oversized service_type value into a fixed-size stack buffer without enforcing a length bound. A valid sessionCheck token is required, and the published proof of concept demonstrates denial of service rather than code execution.
Summary
What happened
Stack-based buffer overflow in TOTOLINK A702R 4.0.0-B20230721.1521 allows remote authenticated users to crash the router. The /boafrm/formPortFw HTTP POST handler copies an oversized service_type value into a fixed-size stack buffer without enforcing a length bound. A valid sessionCheck token is required, and the published proof of concept demonstrates denial of service rather than code execution.
The record
- CVE
- CVE-2025-8139
- Published
- Jul 25, 2025
- Updated
- Jul 25, 2025
- Vendor
- TOTOLINK
- Product
- A702R
- Classifications
- CWE-120, CWE-119, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 25, 2025CVE publishedPublication date reported by the CVE source.
- Jul 25, 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=4.0.0-B20230721.1521
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
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
- TOTOLink A702R formPortFw 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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