FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a missing bounds check in smartcard_unpack_read_size_align() (libfreerdp/utils/smartcard_pack.c:1703) allows a malicious RDP server to crash the FreeRDP client via a reachable WINPR_ASSERT → abort(). The crash occurs in upstream builds where WITH_VERBOSE_WINPR_ASSERT=ON (default in FreeRDP 3.22.0 / current WinPR CMake defaults). Smartcard redirection must be explicitly enabled by the user (e.g., xfreerdp /smartcard; /smartcard-logon implies /smartcard). Version 3.23.0 fixes the issue.
Weakness
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Freerdp | Freerdp | * | 3.23.0 (excluding) |
Extended Description
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, it can still lead to a denial of service. For example, if a server handles multiple simultaneous connections, and an assert() occurs in one single connection that causes all other connections to be dropped, this is a reachable assertion that leads to a denial of service.