CVE-2025-20352
Published: September 29, 2025
Official Description
Cisco IOS and IOS XE contains a stack-based buffer overflow vulnerability in the Simple Network Management Protocol (SNMP) subsystem that could allow for denial of service or remote code execution. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system.
CISA KEV Advisory
Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability
Cisco IOS and IOS XE contains a stack-based buffer overflow vulnerability in the Simple Network Management Protocol (SNMP) subsystem that could allow for denial of service or remote code execution. A successful exploit could allow a low-privileged attacker to cause the affected system to reload, resulting in a DoS condition, or allow a high-privileged attacker to execute arbitrary code as the root user and obtain full control of the affected system.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Risk Analysis
This high-severity stack-based buffer overflow in Cisco IOS and IOS XE's SNMP subsystem could lead to denial of service or remote code execution. Its presence in CISA's KEV catalog and active exploitation in the wild make it a critical vulnerability, despite a low EPSS score of 0.01857.
This vulnerability is actively being exploited in the wild, as confirmed by its presence in CISA's KEV catalog. The flaw is remotely exploitable, allowing attackers to cause denial of service or execute arbitrary code.
Apply the latest security patches for Cisco IOS and IOS XE to mitigate the SNMP subsystem vulnerability. Disable SNMP if not required, or restrict access to trusted networks to prevent remote exploitation.
Technical Analysis
CVE-2025-20352 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2025-20352 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Affected Vendors & Products
Exploit & PoC Resources
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2025-20352 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1