Cisco fixes 3 high-severity DoS flaws in NX

A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) protocol of Cisco NX-OS Software for the Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, adjacent attacker to cause the IS-IS process to unexpectedly restart, which could cause an affected device to reload. This vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition due to the unexpected restart of the IS-IS process, which could cause the affected device to reload. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2 adjacent to the affected device.

A vulnerability in the Simple Network Management Protocol (SNMP) service of Cisco FXOS Software for Firepower 4100 Series and Firepower 9300 Security Appliances and of Cisco UCS 6300 Series Fabric Interconnects could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to the improper handling of specific SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: This vulnerability affects all supported SNMP versions. To exploit this vulnerability through SNMPv2c or earlier, an attacker must know the SNMP community string that is configured on an affected device. To exploit this vulnerability through SNMPv3, the attacker must have valid credentials for an SNMP user who is configured on the affected device.

A vulnerability in the CLI of Cisco FXOS Software could allow an authenticated, local attacker to create a file or overwrite any file on the filesystem of an affected device, including system files. The vulnerability occurs because there is no validation of parameters when a specific CLI command is used. An attacker could exploit this vulnerability by authenticating to an affected device and using the command at the CLI. A successful exploit could allow the attacker to overwrite any file on the disk of the affected device, including system files. The attacker must have valid administrative credentials on the affected device to exploit this vulnerability.