Code execution via unchecked DNS string copy
Published Feb 28, 2025 · Updated Sep 2, 2025
Buffer overflow in TOTOlink A3002R firmware 1.1.1-B20200824.0128 allows remote authenticated users to execute code or crash the router. The formIpv6Setup handler in /bin/boa passes the attacker-controlled pppoe_dns1 string through strcpy into a fixed-size stack buffer without checking the destination capacity. Exploitation requires authenticated access to the router management interface from an adjacent network and can compromise the device or interrupt service.
Summary
What happened
Buffer overflow in TOTOlink A3002R firmware 1.1.1-B20200824.0128 allows remote authenticated users to execute code or crash the router. The formIpv6Setup handler in /bin/boa passes the attacker-controlled pppoe_dns1 string through strcpy into a fixed-size stack buffer without checking the destination capacity. Exploitation requires authenticated access to the router management interface from an adjacent network and can compromise the device or interrupt service.
The record
- CVE
- CVE-2025-25635
- Published
- Feb 28, 2025
- Updated
- Sep 2, 2025
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-120, T1190
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 28, 2025CVE publishedPublication date reported by the CVE source.
- Sep 2, 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?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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
- A3002R formIpv6Setup pppoe_dns1 proof of conceptproof of concept · unverified
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Technologies
Your stack
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Your stack
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