toctou_issue_with_commbuffer.md

6. TOCTOU Issue with CommBuffer {#toctou-issue-with-commbuffer}

Description:

Values from CommBuffer could be changed by DMA, running in parallel with SMM, leading to a buffer overflow during a memory copy operation.

Recommendation:

This issue is addressed by EDK2 SVN https://sourceforge.net/p/edk2/code/14325 and https://sourceforge.net/p/edk2/code/14379.

Acknowledgments:

Reported by the Advanced Threat Research team at Intel Security.