Multiple integer overflows in the Pre-EFI Initialization (PEI) boot phase in the Capsule Update feature in the UEFI implementation in EDK2 allow physically proximate attackers to bypass intended access restrictions by providing crafted data that is not properly handled during the coalescing phase.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
| Link | Tags |
|---|---|
| http://www.kb.cert.org/vuls/id/552286 | third party advisory us government resource |