LibRaw Heap-Based Buffer Overflow Vulnerability in X3F Thumbnail Loader

A heap-based buffer overflow vulnerability has been identified in the LibRaw library, specifically in the X3F thumbnail loading functionality of commit d20315b. This vulnerability arises because the size calculation for thumbnail buffers uses 32-bit arithmetic, which can be manipulated to overflow when processing dimension values controlled by an attacker. As a result, a specially crafted malicious file can lead to a heap buffer overflow, potentially allowing for heap corruption and arbitrary code execution.

Impact

Exploitation of this vulnerability causes a heap-based buffer overflow, leading to heap corruption and the possibility of arbitrary code execution.

Reproduction

The vulnerability can be reproduced by providing a malicious X3F file that exploits the thumbnail loading function in LibRaw. The crafted file must include dimension values that, when processed, cause a 32-bit integer overflow in the thumbnail size calculation. This can be achieved by manipulating the 'columns' and 'rows' values to exceed the maximum limit, causing the allocated buffer to be significantly smaller than required. Once the buffer overflow occurs, the vulnerability can be triggered by extracting the thumbnail data, which will overwrite adjacent memory and potentially allow for code execution.

Remediation

LibRaw has released a patch for this vulnerability. Users should update to the latest version available on the LibRaw GitHub repository.