Linkstrain-ng Slideshow

Lexmark encrypts the firmware update packages provided to consumers, making the binary analysis more difficult. With little over a month of research time assigned and few targets to look at, NCC Group decided to remove the flash memory and extract the firmware using a programmer, firmware which we (correctly) assumed would be stored unencrypted. This allowed us to bypass the firmware update package encryption. With the firmware extracted, the binaries could be reverse-engineered to find vulnerabilities that would allow remote code execution.

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Summary

Bypassing software update package encryption – extracting the Lexmark MC3224i printer firmware (part 1)

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