This advisory documents the impact of an internally found vulnerability in Arista EOS for security ACL bypass. The impact of this vulnerability is that the security ACL drop rule might be bypassed if a NAT ACL rule filter with permit action matches the packet flow. This could allow a host with an IP address in a range that matches the range allowed by a NAT ACL and a range denied by a Security ACL to be forwarded incorrectly as it should have been denied by the Security ACL. This can enable an ACL bypass.
For certain systems running EOS, a Precision Time Protocol (PTP) packet of a management/signaling message with an invalid Type-Length-Value (TLV) causes the PTP agent to restart. Repeated restarts of the service will make the service unavailable.
On affected platforms running Arista EOS with SNMP configured, a specially crafted packet can cause a memory leak in the snmpd process. This may result in the snmpd processing being terminated (causing SNMP requests to time out until snmpd is automatically restarted) and potential memory resource exhaustion for other processes on the switch. The vulnerability does not have any confidentiality or integrity impacts to the system.
On affected modular platforms running Arista EOS equipped with both redundant supervisor modules and having the redundancy protocol configured with RPR or SSO, an existing unprivileged user can login to the standby supervisor as a root user, leading to a privilege escalation. Valid user credentials are required in order to exploit this vulnerability.
On the affected platforms running EOS, a malformed DHCP packet might cause the DHCP relay agent to restart.
An issue has recently been discovered in Arista EOS where, under certain conditions, the service ACL configured for OpenConfig gNOI and OpenConfig RESTCONF might be bypassed, which results in the denied requests being forwarded to the agent.
An issue has recently been discovered in Arista EOS where certain gNOI APIs incorrectly skip authorization and authentication which could potentially allow a factory reset of the device.
An issue has recently been discovered in Arista EOS where the incorrect use of EOS's AAA API’s by the OpenConfig and TerminAttr agents could result in unrestricted access to the device for local users with nopassword configuration.
On affected platforms running Arista EOS, an authorized attacker with permissions to perform gNMI requests could craft a request allowing it to update arbitrary configurations in the switch. This situation occurs only when the Streaming Telemetry Agent (referred to as the TerminAttr agent) is enabled and gNMI access is configured on the agent. Note: This gNMI over the Streaming Telemetry Agent scenario is mostly commonly used when streaming to a 3rd party system and is not used by default when streaming to CloudVision