CVE-2021-22555

En el archivo net/netfilter/x_tables.c se ha detectado una escritura fuera de límites en la pila que afecta a Linux desde la versión 2.6.19-rc1. Esto permite a un atacante alcanzar privilegios o causar una denegación de servicio (por medio de corrupción de la memoria de la pila) mediante el espacio de nombres de usuario

A flaw was discovered in processing setsockopt IPT_SO_SET_REPLACE (or IP6T_SO_SET_REPLACE) for 32 bit processes on 64 bit systems. This flaw will allow local user to gain privileges or cause a DoS through user name space. This action is usually restricted to root-privileged users but can also be leveraged if the kernel is compiled with CONFIG_USER_NS and CONFIG_NET_NS and the user is granted elevated privileges.

A heap out-of-bounds write affecting Linux since version 2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a denial of service (via heap memory corruption) through user name space. Kernels up to and including 5.11 are vulnerable.