Authenticated memory corruption via unchecked sprintf
Published May 4, 2026 · Updated May 4, 2026
Buffer overflow in TOTOLINK N300RH firmware 3.2.4-B20220812 allows remote authenticated users to corrupt device memory via a POST request. The setMacFilterRules handler in /cgi-bin/cstecgi.cgi passes the attacker-controlled mac_address value from the POST body to sprintf without checking its length, overflowing the destination buffer. Low-privilege access to the web interface is required, and the public record does not establish whether exploitation produces a crash or controlled code execution.
Summary
What happened
Buffer overflow in TOTOLINK N300RH firmware 3.2.4-B20220812 allows remote authenticated users to corrupt device memory via a POST request. The setMacFilterRules handler in /cgi-bin/cstecgi.cgi passes the attacker-controlled mac_address value from the POST body to sprintf without checking its length, overflowing the destination buffer. Low-privilege access to the web interface is required, and the public record does not establish whether exploitation produces a crash or controlled code execution.
The record
- CVE
- CVE-2026-7750
- Published
- May 4, 2026
- Updated
- May 4, 2026
- Vendor
- TOTOLINK
- Product
- N300RH Firmware
- Classifications
- CWE-119, CWE-120, T1190
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- May 4, 2026CVE publishedPublication date reported by the CVE source.
- May 4, 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=3.2.4-B20220812
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
- TOTOLINK N300RH setMacFilterRules proof of conceptproof of concept · unverified
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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