CWE-127 - Buffer Under-read

CWE ID:

CWE-127

Abstraction:Variant
Structure:Simple
Status:Draft

Release Date:2006-07-19
Latest Modification Date:2023-10-26

Weakness Name

Buffer Under-read

Description

The product reads from a buffer using buffer access mechanisms such as indexes or pointers that reference memory locations prior to the targeted buffer.

This typically occurs when the pointer or its index is decremented to a position before the buffer, when pointer arithmetic results in a position before the beginning of the valid memory location, or when a negative index is used. This may result in exposure of sensitive information or possibly a crash.

Common Consequences

Scope: Confidentiality

Impact: Read Memory

Scope: Confidentiality

Impact: Bypass Protection Mechanism

Notes: By reading out-of-bounds memory, an attacker might be able to get secret values, such as memory addresses, which can be bypass protection mechanisms such as ASLR in order to improve the reliability and likelihood of exploiting a separate weakness to achieve code execution instead of just denial of service.