CVE-2020-3516 Cisco IOS XE Software Web UI Improper Input Validation Vulnerability
An authenticated remote attacker can crash the web server on Cisco IOS XE devices by sending unexpected characters during authentication, requiring manual recovery.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-3516?
CVE-2020-3516 is a medium-severity denial of service vulnerability in Cisco Ios Xe, published on 24 Sep 2020. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
A vulnerability in the web server authentication of Cisco IOS XE Software could allow an authenticated, remote attacker to crash the web server on the device. The vulnerability is due to insufficient input validation during authentication. An attacker could exploit this vulnerability by entering unexpected characters during a valid authentication. A successful exploit could allow the attacker to crash the web server on the device, which must be manually recovered by disabling and re-enabling the web server.
Weakness: CWE-20
Which versions are affected by CVE-2020-3516?
It affects 1 product.
Products include Cisco Ios Xe.
How do I fix CVE-2020-3516?
No fix has been published for CVE-2020-3516 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-2020-3516 being exploited?
There is no known exploitation of CVE-2020-3516 in the wild and no public exploit code.
Other vulnerabilities in Cisco Ios Xe
- CVE-2023-20198 Cisco IOS XE Web UI Privilege Escalation
- CVE-2018-0151 Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution
- CVE-2023-20273 Cisco IOS XE Web UI Command Injection
- CVE-2025-20188 Hardcoded credentials in Cisco IOS XE Software
- CVE-2021-34770 Cisco IOS XE Software for Catalyst 9000 Family Wireless Controllers CAPWAP Remote Code Execution Vulnerability
Sources
Also known as GHSA-c38h-42jg-3h9q.