Memory corruption while using alignments for memory allocation.
Critical memory corruption vulnerability allows for arbitrary code execution. Exploitation leverages improper handling of memory alignments during allocation, potentially leading to system compromise. Successful exploitation grants attackers the ability to execute malicious code with elevated privileges, posing a significant risk to data confidentiality and system integrity.
Step 1: Trigger Condition: The attacker crafts a malicious input that triggers the vulnerable memory allocation code path, likely by providing specific alignment parameters or allocation sizes.
Step 2: Alignment Calculation Flaw: The memory allocation routine incorrectly calculates the memory address due to an integer overflow or underflow during alignment calculations.
Step 3: Memory Corruption: The incorrect address calculation results in writing data outside the allocated buffer, leading to a heap overflow or out-of-bounds write.
Step 4: Controlled Overwrite: The attacker's crafted input allows them to control the data written to the corrupted memory region, potentially overwriting critical data structures or function pointers.
Step 5: Code Execution: By overwriting a function pointer or other control data, the attacker redirects program execution to their malicious code, achieving arbitrary code execution with the privileges of the vulnerable process.
The vulnerability stems from a flaw in the memory allocation routines, specifically related to how memory is aligned. The root cause is likely an integer overflow or underflow during the calculation of the allocation size or offset, when combined with the alignment requirements. This leads to a heap overflow or heap out-of-bounds write. The attacker can control the size and potentially the alignment parameters, allowing them to overwrite adjacent memory regions. This could overwrite critical data structures, function pointers, or other sensitive information, leading to arbitrary code execution. The specific function or logic flaw is likely within the memory allocation library's alignment calculation and memory copy routines. The vulnerability is exacerbated by the lack of proper bounds checking and validation of the alignment parameters, allowing for the creation of an exploitable condition. The vulnerability could also be a use-after-free condition if the memory is freed and then accessed again.