Cisco has fixed a high-severity zero-day vulnerability (CVE-2025-20352) that affects its Cisco IOS and IOS XE software. The flaw is located in the Simple Network Management Protocol (SNMP) subsystem and can be exploited by remote authenticated attackers to trigger a denial of service (DoS) or execute root code.
The vulnerability, which impacts all devices with SNMP enabled, allows an attacker with low privileges to cause a DoS condition, while an attacker with high privileges can execute code as the root user. However, no workarounds are available for this issue, and Cisco recommends upgrading to a fixed software release.
To mitigate the risk, Cisco suggests restricting SNMP access on affected systems to trusted users until a patch is available. The company’s Product Security Incident Response Team (PSIRT) has confirmed that attacks in the wild are exploiting this vulnerability, highlighting the urgency of the fix.
Source: https://securityaffairs.com/182564/hacking/cisco-fixed-actively-exploited-zero-day-in-cisco-ios-and-ios-xe-software.html