Security Advisory
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Security Advisory
1.0.0
Security Advisory
1. Insecure Default Secure Boot Policy for Option ROMs
2. Incorrect PKCS#1v1.5 Padding Verification for RSA Signature Check
3. UEFI Variable “Reinstallation”
4. Overwrite from Performance Data Variable
5. CommBuffer SMM Overwrite/Exposure
6. TOCTOU Issue with CommBuffer
7. SMRAM Overwrite in Fault Tolerant Write SMI Handler
8. SMRAM Overwrite in SmmVariableHandler
9. Integer/Heap Overflow in SetVariable
10. Heap Overflow in UpdateVariable
11. Overwrite from FirmwarePerformance Variable
12. Integer/Buffer Overflow in TpmDxe Driver
13. Protection of PhysicalPresence Variable
14. Boot Failure Related to UEFI Variable Usage
15. Buffer Overflows in Capsule Update
16. Boot Failure Related to TPM Measurements
17. Buffer Overflow in Variable Reclaim
18. Overflow in Processing of AuthVarKeyDatabase
19. Counter Based Authenticated Variable Issue
20. Honoring Memory Only Reset Control and correct MOR spec imlementation
21. TCG PP S4 issue
22. BIOS Password
23. OPAL driver has PP issue on BlockSid
24. OPAL driver has PSID issue
25. DHCP misses boundary check for network packet
26. SmmCore comm buffer check has TOCTOU issue
27. UEFI Variable Deletion/Corruption
28. EDK II Untested memory not covered by SMM page protection
29. Unauthenticated Firmware Chain-of-Trust Bypass
30. EDK II Authenticated Variable Bypass
31. EDK II TianoCompress Bounds Checking Issues
32. DNS Packet Size Check
33. Opal BlockSid Setting Disabled after S3
34. PartitionDxe and Udf Buffer Overflow
35. Stack Overflow on Corrupted BMP
36. Buffer Overflow in BlockIo service for RAM disk
37. XHCI stack local stack overflow
38. SW SMI Confused Deputy SmramSaveState.c
39. Unlimited FV Recursion
40. AuthVariable Timestamp Zeroing on APPEND_WRITE
41. BootGuard TOCTOU
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17. Buffer Overflow in Variable Reclaim

Description:

The Reclaim function that performs garbage collection on the UEFI variable storage area in flash contained a bug that allowed it to search beyond the bounds of the variable storage area. In this circumstance, a buffer overflow may occur. This may result in elevation of privilege or denial of service.
NOTE: This issue would not normally be exposed. In order to exploit this issue, a separate vulnerability must allow modification of the variable storage area and regions after it, normally stored on SPI flash.
However, because the existing implementation depended upon data outside the variable store, this was considered a security issue and mitigated in code that is intended to be used in production.

Recommendation:

The issue was initially reported in FSVariable.c, which is not intended for use in production. EDK2 SVN https://sourceforge.net/p/edk2/code/16217 and https://sourceforge.net/p/edk2/code/16218 introduce comments to clarify that the code is not intended for production use.
Updates to the Reclaim function in MdeModulePkg and SecurityPkg in EDK2 were made in EDK2 SVN https://sourceforge.net/p/edk2/code/16280.

Acknowledgments:

Reported by Rafal Wojtczuk from Bromium and Corey Kallenberg from MITRE.

References:

• CERT/CC VU#533140 • USRT M1247
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