HTTP service crash via unchecked dnsserver1 copy
Published Jun 17, 2025 · Updated Jul 15, 2025
Buffer overflow in TP-Link TL-WR940N V4 through 160617 and TL-WR841N V11 through 160325 allows remote authenticated users to crash HTTP. On TL-WR940N, sub_44E6E0 retrieves dnsserver1 with httpGetEnv and copies it with strcpy without checking its length; TP-Link has not published equivalent code-level detail for TL-WR841N. High-privilege access to the web-management endpoint is required; exploitation crashes HTTP, recoverable by reset on TL-WR940N or reboot on TL-WR841N.
Summary
What happened
Buffer overflow in TP-Link TL-WR940N V4 through 160617 and TL-WR841N V11 through 160325 allows remote authenticated users to crash HTTP. On TL-WR940N, sub_44E6E0 retrieves dnsserver1 with httpGetEnv and copies it with strcpy without checking its length; TP-Link has not published equivalent code-level detail for TL-WR841N. High-privilege access to the web-management endpoint is required; exploitation crashes HTTP, recoverable by reset on TL-WR940N or reboot on TL-WR841N.
The record
- CVE
- CVE-2025-6151
- Published
- Jun 17, 2025
- Updated
- Jul 15, 2025
- Vendor
- TP-Link Systems Inc.
- Product
- TL-WR940N
- Classifications
- CWE-120, T1499
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jun 17, 2025CVE publishedPublication date reported by the CVE source.
- Jul 15, 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=0 <=160617
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
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Public exploit references
- TL-WR940N dnsserver1 crash proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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