Cisco IOS Xe 17.15.2a

Cisco IOS XE Software Security Hardening Release

Cisco IOS XE Software Security Hardening Release

Cisco IOS Software and IOS XE Software Extensible Messaging Client Protocol Denial of Service Vulnerability

Cisco IOS XE Software Security Hardening Release

Cisco IOS XE Software Security Hardening Release

Cisco IOS XE Software Security Hardening Release

Cisco IOS XE Software Security Hardening Release

Cisco IOS XE Software Security Hardening Release

A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following: An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials. An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks. This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system. Note: This vulnerability affects all versions of SNMP.

Cisco IOS XE Software SNMP Denial of Service Vulnerability

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS XE Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper error handling when parsing a specific SNMP request. An attacker could exploit this vulnerability by sending a specific SNMP request to an affected device. A successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMPv2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMPv3, the attacker must have valid SNMP user credentials for the affected system.

A vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an egress port to become blocked and drop all outbound traffic. This vulnerability is due to improper handling of crafted Ethernet frames. An attacker could exploit this vulnerability by sending crafted Ethernet frames through an affected switch. A successful exploit could allow the attacker to cause the egress port to which the crafted frame is forwarded to start dropping all frames, resulting in a denial of service (DoS) condition.

Multiple vulnerabilities in Cisco IOS XE Software of could allow an authenticated, local attacker with level-15 privileges or an unauthenticated attacker with physical access to the device to execute persistent code at boot time and break the chain of trust. These vulnerabilities are due path traversal and improper image integrity validation. A successful exploit could allow the attacker to execute persistent code on the underlying operating system. Because this allows the attacker to bypass a major security feature of the device, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High. For more information about these vulnerabilities, see the Details ["#details"] section of this advisory. ERP

A vulnerability in the CLI of Cisco IOS XE Software could allow an authenticated, local attacker with administrative privileges to execute arbitrary commands as root on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of user arguments that are passed to specific CLI commands. An attacker could exploit this vulnerability by logging in to the device CLI with valid administrative (level 15) credentials and using crafted commands at the CLI prompt. A successful exploit could allow the attacker to execute arbitrary commands as root.

A vulnerability in the Cisco IOx application hosting environment of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the Cisco IOx application hosting environment to stop responding, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to cause the Cisco IOx application hosting environment to stop responding. The IOx process will need to be manually restarted to recover services.