Root password prediction via low-entropy MAC derivation
Published Jun 30, 2025 · Updated Jul 1, 2025
Insufficient entropy in D-Link DCS-6517 and DCS-7517 firmware 2.02.0 and earlier allows remote attackers to predict the root password. The /bin/httpd generate_pass_from_mac function derives the root credential from the device MAC address with too little randomness. Unauthenticated network access is sufficient, but high attack complexity limits exploitation to confidentiality exposure, with no reported data modification or service interruption.
Summary
What happened
Insufficient entropy in D-Link DCS-6517 and DCS-7517 firmware 2.02.0 and earlier allows remote attackers to predict the root password. The /bin/httpd generate_pass_from_mac function derives the root credential from the device MAC address with too little randomness. Unauthenticated network access is sufficient, but high attack complexity limits exploitation to confidentiality exposure, with no reported data modification or service interruption.
The record
- CVE
- CVE-2025-6931
- Published
- Jun 30, 2025
- Updated
- Jul 1, 2025
- Vendor
- D-Link
- Product
- DCS-6517
- Classifications
- CWE-331, CWE-330, T1110
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 30, 2025CVE publishedPublication date reported by the CVE source.
- Jul 1, 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=2.02
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
- DCS-6517B1 firmware 2.02.01 analysis reportproof of concept · unverified
- DCS-7517 B1 firmware 2.02.01 analysis reportproof 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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