CVE-2020-11089: 
NixOS vulnerability analysis and mitigation

CVE-2020-11089 affects FreeRDP, a free implementation of the Remote Desktop Protocol (RDP). The vulnerability was discovered in versions before 2.1.0 and involves an out-of-bounds read in irp functions, specifically affecting parallel_process_irp_create, serial_process_irp_create, drive_process_irp_write, printer_process_irp_write, rdpei_recv_pdu, and serial_process_irp_write functions (OpenSUSE Advisory, GitHub Advisory).

The vulnerability is characterized by an out-of-bounds read condition in multiple IRP (I/O Request Packet) functions. This affects FreeRDP clients which support parallel port, serial port, drive, printer and multitouch redirection. The issue was addressed with patches 795842f and 6b485b1, which implemented proper bounds checking and safe memory handling in the affected functions (GitHub Advisory).

The vulnerability affects FreeRDP clients using parallel port, serial port, drive, printer, and multitouch redirection features. When exploited, it could allow an attacker to cause out-of-bounds memory reads, potentially leading to information disclosure or application crashes (Red Hat Advisory).

The vulnerability can be triggered when using specific FreeRDP client features including /parallel, /drive, /serial, /printer or +multitouch command line options. No known exploits in the wild have been reported (GitHub Advisory).

The primary mitigation is to upgrade to FreeRDP version 2.1.0 or newer which contains the security fixes. As a workaround, users can disable the affected features by not using the /parallel, /drive, /serial, /printer or +multitouch command line options (GitHub Advisory).