This was a presentation given at BSides Rochester in 2024. It goes over how we dumped the firmware, fuzzed the post script engine, and gained code execution by exploiting a memory corruption bug. https://www.oneupsecurity.com/wp-content/uploads/2024/03/Lexmark-Printer-Remote-Code-Execution-via-Memory-Corruption-Presentation.pdf
Research
CVE-2020-16225: TPEditor v1.96 Code Execution via Memory Corruption
TLDR; TPEditor v1.96 does not perform bound checking when copying “boot page” (.sta) file content to memory. The finding can be exploited to gain arbitrary code execution upon file opening. [ZDI Link] This bug was a bit interesting. VirtualAlloc() is used to allocate memory and returns a pointer to an allocation. However, we can trigger a […]
CVE-2021-29084: Exploiting CRLF Header Injection in Synology NAS for Unauthenticated File Downloads
Recently our CVE-2021-29084 went public [ZDI Link]. We thought it would be fun to share our disclosure notes. The Synology DS418play NAS contained an unauthenticated accessible endpoint vulnerable to HTTP header injection. Due to nginx’s configuration, the X-Accel-Redirect header can be used download files which are shared via SMB. Note the finding requires knowledge of […]
Unauthenticated File Deletion in Synology NAS DS418play
The Synology DS418play NAS contained an unauthenticated endpoint which can be leveraged to delete arbitrary files. The exploit can be used to bypass account login throttling by deleting a database file containing banned IP addresses. The finding could potentially lead to soft bricking the device too, such as by deleting system files. The unauthenticated OTP admin […]
Five Minute Guide to Software Security
Education & designing secure software through hardened frameworks is the best way to mitigate security breaches. Security is not only a business decision, but also a moral decision. Always seek advice from an experienced security professional.
Remote Code Execution In Source Games
Valve’s Source SDK contained a buffer overflow vulnerability which allowed remote code execution on clients and servers. The vulnerability was exploited by fragging a player, which caused a specially crafted ragdoll model to be loaded. Multiple Source games were updated during the month of June 2017 to fix the vulnerability.