DoS Vulnerability in Cisco IOS and IOS XE Software SNMP Subsystem

CVE-2025-20169

What is CVE-2025-20169?

CVE-2025-20169 is a serious vulnerability found in the SNMP (Simple Network Management Protocol) subsystem of Cisco’s IOS and IOS XE software, which are widely used for networking devices such as routers and switches. This vulnerability allows an authenticated remote attacker to send specially crafted SNMP requests that can trigger a denial-of-service (DoS) condition on affected devices. If exploited, it may lead to unexpected device reloads, causing service interruptions that can significantly impact network stability and availability for organizations.

Technical Details

The vulnerability arises from improper error handling in the SNMP subsystem when handling SNMP requests. Specifically, it affects SNMP versions 1, 2c, and 3. To exploit this vulnerability, an attacker must possess the appropriate credentials: valid SNMP community strings for SNMP v2c or earlier, or valid SNMP user credentials for SNMP v3. When a malicious actor sends a crafted SNMP request, it can result in the device rebooting unexpectedly, thus creating a denial-of-service situation.

Potential Impact of CVE-2025-20169

1. Service Disruption: Successful exploitation can lead to unexpected reboots of affected devices, resulting in prolonged outages and a loss of service for users relying on those network systems.

2. Increased Operational Costs: Organizations may incur additional costs related to troubleshooting and restoring service, which can divert IT resources from other critical tasks.

3. Network Vulnerability: Repeated DoS incidents might expose the network to further attacks, as devices may become unresponsive, making them prime targets for additional exploit attempts or unauthorized access.

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