CVE-2020-3526 Cisco IOS XE Software Common Open Policy Service Engine Denial of Service Vulnerability

What is CVE-2020-3526?

CVE-2020-3526 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 24 Sep 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A vulnerability in the Common Open Policy Service (COPS) engine of Cisco IOS XE Software on Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to crash a device. The vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a malformed COPS message to the device. A successful exploit could allow the attacker to crash the device.

Weakness: CWE-20

Which versions are affected by CVE-2020-3526?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2020-3526?

No fix has been published for CVE-2020-3526 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2020-3526 being exploited?

There is no known exploitation of CVE-2020-3526 in the wild and no public exploit code.

Other vulnerabilities in Cisco Ios Xe

• CVE-2023-20198 Cisco IOS XE Web UI Privilege Escalation Exploited Critical 10.0
• CVE-2018-0151 Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution Exploited Critical 9.8
• CVE-2023-20273 Cisco IOS XE Web UI Command Injection Exploited High 7.2
• CVE-2025-20188 Hardcoded credentials in Cisco IOS XE Software Critical 10.0
• CVE-2021-34770 Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Remote Code Execution Vulnerability Critical 10.0

All Cisco Ios Xe vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-x9r4-mp46-hrqx.