Zero-day vulnerability in Cisco IOS XE

Stack-based buffer overflow
CVE-2025-20352

Vulnerability details

Advisory: SB2025092462 - Authenticated code execution in Cisco IOS and IOS XE SNMP implementation

Vulnerable component: Cisco IOS XE

CVE-ID: CVE-2025-20352

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-121 - Stack-based buffer overflow

Description:

The vulnerability allows a remote user to compromise the affected system.

The vulnerability exists due to a boundary error within the SNMP subsystem. A remote privileged user can send specially crafted SNMP packets to the affected device, trigger a stack-based buffer overflow and execute arbitrary code with root privileges. 

Note, the vulnerability is being actively exploited in the wild. 

External links:

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-snmp-x4LPhte

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.