CVE-2021-3595

Se ha encontrado un problema de inicialización de puntero no válido en la implementación de redes SLiRP de QEMU. El fallo se presenta en la función tftp_input() y podría ocurrir mientras se procesa un paquete udp más pequeño que el tamaño de la estructura "tftp_t". Este problema puede conllevar a un acceso de lectura fuera de límites o a una divulgación indirecta de la memoria del host al invitado. La mayor amenaza de esta vulnerabilidad es la confidencialidad de los datos. Este fallo afecta a libslirp versiones anteriores a 4.6.0

An invalid pointer initialization issue was found in the SLiRP networking implementation of QEMU. The flaw exists in the tftp_input() function and could occur while processing a udp packet that is smaller than the size of the 'tftp_t' structure. This issue may lead to out-of-bounds read access or indirect host memory disclosure to the guest. The highest threat from this vulnerability is to data confidentiality.

USN-5009-1 fixed vulnerabilities in libslirp. This update provides the corresponding updates for Ubuntu 21.10. Qiuhao Li discovered that libslirp incorrectly handled certain header data lengths. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. This issue only affected Ubuntu 20.04 LTS and Ubuntu 20.10. It was discovered that libslirp incorrectly handled certain udp packets. An attacker inside a guest could possibly use this issue to leak sensitive information from the host. Various other issues were also addressed.