Cisco SNMP exploit targets IOS and IOS XE devices: What it means for your network

CVE-2025-20352

SNMP has always been one of the quiet but crucial components of network management. It helps administrators monitor devices, automate configurations, and keep operations running smoothly.

On Sept. 24, 2025, Cisco disclosed a high-severity vulnerability, identified as CVE-2025-20352, affecting the SNMP implementation in its IOS and IOS XE software. This issue allows attackers with valid SNMP credentials to cause a denial of service or execute arbitrary code on the affected devices. In simpler terms, if someone gains valid SNMP access, they could crash your routers or, take control of them.

With a CVSS score of 7.7 (High) and confirmed active exploitation, this issue demands immediate attention. Cisco recommends reviewing SNMP configurations, removing unused or unauthorized users, and updating to the latest fixed software releases listed in their official advisory.

How attackers can leverage SNMP access

SNMP remains a backbone of network monitoring and management, but its wide accessibility also makes it a prime target. Once a malicious actor gains valid SNMP credentials, they can exploit this vulnerability to disrupt services or take control of devices. This access can be used to disrupt operations, gather network data, or compromise other connected systems. In large network environments, identifying and removing unauthorized SNMP users manually isn't scalable. Devices often run different versions or configurations, and missing even one unapproved account can leave your network exposed.

Automate SNMP user cleanup with Network Configuration Manager 

This is where ManageEngine Network Configuration Manager provides a critical advantage. Instead of logging into each device and editing configurations manually, administrators can use Programmable Configlets to automate these actions across all Cisco devices.

A single configlet can:

  • Fetch SNMP user details from multiple Cisco devices.
  • Compare them against an approved list of authorized users.
  • Automatically remove unauthorized or unknown SNMP accounts.

You can also add user-defined parameters, such as a multi-select list of approved SNMP users, to ensure the Configlet keeps trusted accounts while removing unauthorized accounts. This approach combines intelligent scripting, dynamic logic, and scalable automation, allowing you to standardize security changes across your entire network with precision and speed.

What’s next: ComplianceIQ

ManageEngine will soon introduce ComplianceIQ, an advanced compliance management engine built into Network Configuration Manager. ComplianceIQ will automatically evaluate device configurations, identify policy violations such as unauthorized SNMP users, and guide administrators through remediation steps. It helps you maintain compliance effortlessly while ensuring your network stays secure against evolving threats like CVE-2025-20352.

Final takeaway

Cisco's SNMP vulnerability is another reminder that even trusted management protocols can become gateways for attackers when overlooked. By integrating Network Configuration Manager into your vulnerability response workflow, you can automate remediation, enforce compliance, and stay one step ahead of evolving network threats.

Try ManageEngine Network Configuration Manager for free!