CVE-2018-17204

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting parse_group_prop_ntr_selection_method in lib/ofp-util.c. When decoding a group mod, it validates the group type and command after the whole group mod has been decoded. The OF1.5 decoder, however, tries to use the type and command earlier, when it might still be invalid. This causes an assertion failure (via OVS_NOT_REACHED). ovs-vswitchd does not enable support for OpenFlow 1.5 by default.

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting parse_group_prop_ntr_selection_method in lib/ofp-util.c. When decoding a group mod, it validates the group type and command after the whole group mod has been decoded. The OF1.5 decoder, however, tries to use the type and command earlier, when it might still be invalid. This causes an assertion failure (via OVS_NOT_REACHED). ovs-vswitchd does not enable support for OpenFlow 1.5 by default.

Se ha descubierto un problema en Open vSwitch (OvS) en versiones 2.7.x hasta la 2.7.6 que afecta a parse_group_prop_ntr_selection_method en lib/ofp-util.c. Cuando se descodifica un mod de grupo, valida el tipo de grupo y comando después de que todo el mod de grupo se haya descodificado. Sin embargo, el decodificador OF1.5 intenta utilizar el tipo y comando antes, cuando puede ser todavía no válido. Esto provoca un fallo de aserción (mediante OVS_NOT_REACHED). ovs-vswitchd tiene deshabilitado el soporte para OpenFlow 1.5 por defecto.