CVE-2018-14498

What it actually does

Heap-based buffer over-read in get_8bit_row when parsing an 8-bit BMP with color indices exceeding the palette size, resulting in application crash.

Why it matters to the business

Image-processing applications and services can be crashed by specially crafted image files, leading to denial of service and operational disruption until the process is restarted.

How an attack unfolds

An attacker creates a malicious 8-bit BMP file where one or more palette indices are larger than the actual number of palette entries and delivers the file to a victim application that uses the vulnerable libjpeg-turbo library; when the library attempts to read the row data, the out-of-range index triggers the buffer over-read and crash.

How to fix it

Upgrade libjpeg-turbo to the commit 9c78a04df4e44ef6487eee99c4258397f4fdca55 or later; rebuild and redeploy all dependent applications and libraries that statically or dynamically link the affected version.

How to confirm the fix worked

Confirm the installed libjpeg-turbo binary or source matches or exceeds commit 9c78a04df4e44ef6487eee99c4258397f4fdca55; re-test with the original proof-of-concept BMP to verify the crash no longer occurs.

Typical attack path

1. Craft a BMP image with an 8-bit palette and out-of-range color indices
2. Host or transmit the malformed image to a target that processes it with libjpeg-turbo
3. Trigger image decoding in the vulnerable code path
4. Cause heap over-read and subsequent application crash

How to detect it

Monitor application and system logs for unexpected crashes or segmentation faults during BMP decoding; review process dumps or core files that show faults originating in rdbmp.c or get_8bit_row.

What your security team should do

• Prioritize upgrade of libjpeg-turbo in all image-handling services within the next maintenance window
• Scan build pipelines and container images for the vulnerable commit range and enforce the fixed version
• Add the malicious BMP pattern to regression test suites for image parsers