Authenticated code execution via unchecked qosClassifier parameters
Published Aug 24, 2025 · Updated Aug 25, 2025
Stack-based buffer overflow in Linksys RE series firmware allows remote authenticated users to execute code through qosClassifier requests. In mod_form.so, qosClassifier copies nine unchecked form parameters into stack-local storage, allowing oversized values to overwrite its return address. Access requires a valid session cookie; the published proof of concept demonstrates a device crash, while the researcher reports control-flow overwrite enabling code execution.
Summary
What happened
Stack-based buffer overflow in Linksys RE series firmware allows remote authenticated users to execute code through qosClassifier requests. In mod_form.so, qosClassifier copies nine unchecked form parameters into stack-local storage, allowing oversized values to overwrite its return address. Access requires a valid session cookie; the published proof of concept demonstrates a device crash, while the researcher reports control-flow overwrite enabling code execution.
The record
- CVE
- CVE-2025-9392
- Published
- Aug 24, 2025
- Updated
- Aug 25, 2025
- Vendor
- Linksys
- Product
- RE6250
- Classifications
- CWE-121, CWE-119, T1190, T1499.004
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 24, 2025CVE publishedPublication date reported by the CVE source.
- Aug 25, 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=1.0.013.001
- Affected versionversion=1.0.04.001
- Affected versionversion=1.0.04.002
- Affected versionversion=1.1.05.003
- Affected versionversion=1.2.07.001
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
- Linksys qosClassifier oversized-parameter proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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