Heap Out-of-Bounds Write in AFFLIB

Executive Summary

AFFLIB through 3.7.22 has a heap out-of-bounds write flaw in the af_get_page() function. Attackers exploit this by providing specially crafted AFF images where the page size is larger than and not a multiple of the sector size. This causes the sector zero-fill loop to write beyond the allocated buffer, corrupting heap memory and potentially crashing forensic tools that process these images.

Useful 0 Not Useful 0

Detection Guidance

This vulnerability can be detected by analyzing AFF images for mismatched page and sector sizes. Use tools like affinfo or affcat from AFFLIB to inspect AFF files. Check if page size is larger than or not a multiple of the sector size. Example command: affinfo -p <aff_file> to view page and sector details.

Useful 0 Not Useful 0

Impact Analysis

If you use AFFLIB-based forensic tools to analyze disk images, an attacker could crash these tools by providing a maliciously crafted AFF file. This could disrupt forensic investigations, data recovery, or digital evidence analysis. The crash occurs due to memory corruption, which may also lead to denial-of-service conditions.

Useful 0 Not Useful 0

Compliance Impact

This vulnerability could impact compliance by disrupting forensic investigations required for legal or regulatory purposes. If forensic tools crash while processing evidence, it may lead to incomplete or corrupted data, potentially violating requirements for data integrity and audit trails in standards like GDPR or HIPAA.

Useful 0 Not Useful 0

Mitigation Strategies

Update AFFLIB to version 3.7.23 or later to patch the heap out-of-bounds write issue. Avoid processing untrusted AFF images until updated. If immediate update is not possible, restrict access to AFF files from untrusted sources.

Useful 0 Not Useful 0