Cisco · IOS and IOS XE
CVE-2025-20352
Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability
What it is
A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software could allow the following:
An authenticated, remote attacker with low privileges could cause a denial of service (DoS) condition on an affected device that is running Cisco IOS Software or Cisco IOS XE Software. To cause the DoS, the attacker must have the SNMPv2c or earlier read-only community string or valid SNMPv3 user credentials.
An authenticated, remote attacker with high privileges could execute code as the root user on an affected device that is running Cisco IOS XE Software. To execute code as the root user, the attacker must have the SNMPv1 or v2c read-only community string or valid SNMPv3 user credentials and administrative or privilege 15 credentials on the affected device.
An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device over IPv4 or IPv6 networks.
This vulnerability is due to a stack overflow condition in the SNMP subsystem of the affected software. 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.
Note: This vulnerability affects all versions of SNMP.
CISA: 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.
What to do
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Deadline for US federal agencies: October 20, 2025
More exploited flaws from Cisco
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Oct 10, 2023 | Group Encrypted Transport VPN Out-of-Bounds Write | IOS and IOS XE | Medium 6.6 | 2.5% |
| Mar 25, 2022 | Remote Code Execution | IOS and IOS XE | Critical 9.8 | 99% |
| Nov 3, 2021 | Software Smart Install Remote Code Execution | IOS and IOS XE | High 7.5 | 99.5% |
| Oct 14, 2026 | Relative Path Traversal | Secure Email Gateway | Critical 9.8 | 2.2% |
| Sep 30, 2026 | Hex Encoding | Catalyst SD-WAN Manager | Critical 9.8 | 39% |
| Sep 16, 2026 | Incorrect Use of Privileged APIs | Identity Services Engine | Critical 10.0 | 76% |
| Sep 14, 2026 | SQL Injection | Secure Email Gateway | Critical 9.8 | 30% |
| Sep 9, 2026 | Firewall Management Center Authentication Bypass Using an Alternate Path or Channel | Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management | Critical 10.0 | 88% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.