Root code execution via unsafe CAPTCHA formatting
Published Jul 31, 2025 · Updated May 14, 2026
Stack overflow in D-Link DIR-605L firmware 1.12 through 1.13 allows remote attackers to execute code as root through the login endpoint. The getAuthCode() function passes attacker-controlled CAPTCHA data from the FILECODE parameter in /goform/formLogin to sprintf() without a length bound, overwriting its stack buffer. The endpoint is reachable without authentication, and successful exploitation grants full root-level control of the router.
Summary
What happened
Stack overflow in D-Link DIR-605L firmware 1.12 through 1.13 allows remote attackers to execute code as root through the login endpoint. The getAuthCode() function passes attacker-controlled CAPTCHA data from the FILECODE parameter in /goform/formLogin to sprintf() without a length bound, overwriting its stack buffer. The endpoint is reachable without authentication, and successful exploitation grants full root-level control of the router.
The record
- CVE
- CVE-2012-10021
- Published
- Jul 31, 2025
- Updated
- May 14, 2026
- Vendor
- D-Link
- Product
- DIR-605L
- Classifications
- CWE-121, T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 31, 2025CVE publishedPublication date reported by the CVE source.
- May 14, 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=1.12 <=1.13
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
- D-Link DIR-605L Captcha Handling Buffer Overflow Metasploit modulefunctional · validated
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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