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Cisco Plugs Critical Holes in Catalyst PON Enterprise Switches

Enterprise networking giant Cisco has released patches for multiple vulnerabilities across its product portfolio, including critical security defects in Catalyst Passive Optical Network (PON) series switches and the Policy Suite product.

The most severe of these issues are CVE-2021-34795 and CVE-2021-40113 (CVSS 10.0), two flaws in Catalyst PON switches that could be exploited to log in to a vulnerable device using unintentional debugging credentials, or to perform unauthenticated command injection, Cisco said in an advisory.

The company said CVE-2021-34795 exists in the Telnet service of Cisco Catalyst PON series switches ONT and could be exploited to establish a Telnet session to the device using the default credential. The bug would allow the attacker to take over the vulnerable device.

The second CVE-2021-40113 bug affects the web-based management interface of the enterprise switches and could be exploited remotely, without authentication. Because user-supplied input isn’t sufficiently validated, the flaw allows an attacker to execute commands as root.

[ READ: 'Dangerous Code Execution Flaw in Linux Kernel Module ]

A third vulnerability Cisco addressed in the same products (Catalyst PON switch CGP-ONT-1P, CGP-ONT-4P, CGP-ONT-4PV, CGP-ONT-4PVC, and CGP-ONT-4TVCW models) could be exploited remotely without authentication to modify the configuration of the device. The bug is tracked as CVE-2021-40112 (CVSS 8.6).

This week, Cisco also patched a critical security hole in the key-based SSH authentication mechanism of Policy Suite. Tracked as CVE-2021-40119 (CVSS score of 9.8), the issue could allow an unauthenticated, remote attacker to log into a vulnerable device as root.

The vulnerability exists because static SSH keys are used across installations, meaning that an adversary could extract the keys from an attacker-controlled system and then log in to a vulnerable system.

On Wednesday, Cisco also announced patches for a high-severity vulnerability (CVE-2021-34739, CVSS score 8.1) in small business switches that could allow an attacker to replay valid user session credentials to access a vulnerable device remotely.

READ: High-Severity Flaws in Cisco Security Appliances, Business Switches ]

A high-severity flaw (CVE-2021-34741, CVSS score of 7.5) in AsyncOS software for Cisco Email Security Appliance (ESA) could be exploited by a remote attacker to cause a denial of service condition. The issue exists because of insufficient input validation of incoming emails and does not require authentication for successful exploitation.

Additionally, Cisco released patches for multiple medium-severity security errors in Webex, Umbrella, Prime Infrastructure (PI) and Evolved Programmable Network Manager (EPNM), Unified Communications, Common Services Platform Collector (CSPC), Prime Access Registrar, and AnyConnect Secure Mobility Client for Windows.

However, the company also announced that a couple of medium-severity issues identified in Small Business 200, 300, and 500 series switches and RV series routers will remain unpatched, as these products have reached end-of-life.

Cisco said it was not aware of any of these vulnerabilities being exploited in the wild.

Related: Cisco Patches High-Severity DoS Vulnerabilities in ASA, FTD Software

Related: High-Severity Flaws in Cisco Security Appliances, Business Switches

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