This change addresses a potential buffer over-read in the DNS Response Parser when parsing domain names in a DNS response. A carefully crafted DNS response with domain name length value greater than the actual domain name length, could cause the parser to read beyond the DNS response buffer. This issue affects applications using DNS functionality of the FreeRTOS-Plus-TCP stack. Applications that do not use DNS functionality are not affected, even when the DNS functionality is enabled.
This issue has been fixed by modifying the code to ensure that the DNS Response Parser never attempts to read beyond the DNS response buffer boundary.
We would like to thank Paschal Amusuo, James C. Davis, and Aravind Machiry of Purdue University, for reporting this issue.
Test Steps
Checklist:
[x] I have tested my changes. No regression in existing tests.
[x] I have modified and/or added unit-tests to cover the code changes in this Pull Request.
Related Issue
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Description
This change addresses a potential buffer over-read in the DNS Response Parser when parsing domain names in a DNS response. A carefully crafted DNS response with domain name length value greater than the actual domain name length, could cause the parser to read beyond the DNS response buffer. This issue affects applications using DNS functionality of the FreeRTOS-Plus-TCP stack. Applications that do not use DNS functionality are not affected, even when the DNS functionality is enabled.
This issue has been fixed by modifying the code to ensure that the DNS Response Parser never attempts to read beyond the DNS response buffer boundary.
We would like to thank Paschal Amusuo, James C. Davis, and Aravind Machiry of Purdue University, for reporting this issue.
Test Steps
Checklist:
Related Issue
By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.