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. The decode_bundle function inside lib/ofp-actions.c is affected by a buffer over-read issue during BUNDLE action decoding.

An issue was discovered in Open vSwitch (OvS) 2.7.x through 2.7.6, affecting ofproto_rule_insert__ in ofproto/ofproto.c. During bundle commit, flows that are added in a bundle are applied to ofproto in order. If a flow cannot be added (e.g., the flow action is a go-to for a group id that does not exist), OvS tries to revert back all previous flows that were successfully applied from the same bundle. This is possible since OvS maintains list of old flows that were replaced by flows from the bundle. While reinserting old flows, OvS has an assertion failure due to a check on rule state != RULE_INITIALIZED. This would work for new flows, but for an old flow the rule state is RULE_REMOVED. The assertion failure causes an OvS crash.

In lib/ofp-util.c in Open vSwitch (OvS) before 2.8.1, there are multiple memory leaks while parsing malformed OpenFlow group mod messages. NOTE: the vendor disputes the relevance of this report, stating "it can only be triggered by an OpenFlow controller, but OpenFlow controllers have much more direct and powerful ways to force Open vSwitch to allocate memory, such as by inserting flows into the flow table."

In lib/conntrack.c in the firewall implementation in Open vSwitch (OvS) 2.6.1, there is a buffer over-read while parsing malformed TCP, UDP, and IPv6 packets in the functions `extract_l3_ipv6`, `extract_l4_tcp`, and `extract_l4_udp` that can be triggered remotely.

In Open vSwitch (OvS) 2.5.0, a malformed IP packet can cause the switch to read past the end of the packet buffer due to an unsigned integer underflow in `lib/flow.c` in the function `miniflow_extract`, permitting remote bypass of the access control list enforced by the switch.

In Open vSwitch (OvS) 2.7.0, while parsing an OpenFlow role status message, there is a call to the abort() function for undefined role status reasons in the function `ofp_print_role_status_message` in `lib/ofp-print.c` that may be leveraged toward a remote DoS attack by a malicious switch.

In Open vSwitch (OvS) v2.7.0, there is a buffer over-read while parsing the group mod OpenFlow message sent from the controller in `lib/ofp-util.c` in the function `ofputil_pull_ofp15_group_mod`.

In Open vSwitch (OvS) 2.7.0, while parsing an OFPT_QUEUE_GET_CONFIG_REPLY type OFP 1.0 message, there is a buffer over-read that is caused by an unsigned integer underflow in the function `ofputil_pull_queue_get_config_reply10` in `lib/ofp-util.c`.

Buffer overflow in lib/flow.c in ovs-vswitchd in Open vSwitch 2.2.x and 2.3.x before 2.3.3 and 2.4.x before 2.4.1 allows remote attackers to execute arbitrary code via crafted MPLS packets, as demonstrated by a long string in an ovs-appctl command.