CVE-2025-20352 Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution

Exploited in the wild High 7.7 Published 24 Sep 2025 Updated 26 Feb 2026

Authenticated attackers can cause denial of service or execute arbitrary code as root via crafted SNMP packets due to a stack overflow.

Exploited in the wild: Since 29 Sep 2025
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-20352?

CVE-2025-20352 is a high-severity memory corruption vulnerability in Cisco Ios, published on 24 Sep 2025. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

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.

Weakness: CWE-121

Which versions are affected by CVE-2025-20352?

It affects 3 products.

Products include Cisco Ios, Cisco Ios Xe, Cisco Ios Xe Sd-Wan.

How do I fix CVE-2025-20352?

No fix has been published for CVE-2025-20352 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 20 Oct 2025.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2025-20352 being exploited?

Yes. Attackers have exploited CVE-2025-20352 in the wild since at least 29 Sep 2025.

Public exploit code: 2 proofs of concept on GitHub.

All Cisco Ios vulnerabilities

Sources

Also known as GHSA-c924-mch4-p3p3.