Authenticated code execution via unbounded qos_dat formatting
Published Jan 14, 2025 · Updated Nov 3, 2025
Stack overflow in Wavlink AC3000 M33A8.V5030.210505 allows remote authenticated users to execute arbitrary code via qos.cgi. The qos_settings() function passes the unbounded qos_dat POST value to sprintf while building a command in the 0x500-byte cmdtorun stack buffer, overwriting its return address. A valid session cookie and page=qos request are required; successful exploitation runs attacker-controlled code on the router.
Summary
What happened
Stack overflow in Wavlink AC3000 M33A8.V5030.210505 allows remote authenticated users to execute arbitrary code via qos.cgi. The qos_settings() function passes the unbounded qos_dat POST value to sprintf while building a command in the 0x500-byte cmdtorun stack buffer, overwriting its return address. A valid session cookie and page=qos request are required; successful exploitation runs attacker-controlled code on the router.
The record
- CVE
- CVE-2024-39802
- Published
- Jan 14, 2025
- Updated
- Nov 3, 2025
- Vendor
- Wavlink
- Product
- AC3000 Tri-band Wi-Fi Router
- Classifications
- CWE-120, T1190
- Attack vector
- network
- Privileges
- admin
Timeline
How it unfolded
- Jan 14, 2025CVE publishedPublication date reported by the CVE source.
- Nov 3, 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=M33A8.V5030.210505
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
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
- Cisco Talos qos_dat overflow demonstrationproof of concept · demonstrated
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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