CVE-2014-6055

Múltiples desbordamientos de buffer basado en pila en la caracteristica File Transfer en rfbserver.c en LibVNCServer 0.9.9 y anteriores permiten a usuarios remotos autenticados causar una denegación de servicio (caída) y posiblemente ejecutar código arbitrario a través de un (1) fichero largo o (2) nombre de directorio o el (3) atributo FileTime en un mensaje rfbFileTransferOffer.

Two stack-based buffer overflow flaws were found in the way LibVNCServer handled file transfers. A remote attacker could use this flaw to crash the VNC server using a malicious VNC client.

An integer overflow in liblzo before 2.07 allows attackers to cause a denial of service or possibly code execution in applications using performing LZO decompression on a compressed payload from the attacker. The libvncserver library is built with a bundled copy of minilzo, which is a part of liblzo containing the vulnerable code. A malicious VNC server can trigger incorrect memory management handling by advertising a large screen size parameter to the VNC client. This would result in multiple memory corruptions and could allow remote code execution on the VNC client. A malicious VNC client can trigger multiple DoS conditions on the VNC server by advertising a large screen size, ClientCutText message length and/or a zero scaling factor parameter. A malicious VNC client can trigger multiple stack-based buffer overflows by passing a long file and directory names and/or attributes when using the file transfer message feature.