CVE-2025-20327 Denial of service in IOS
An authenticated low-privilege attacker can cause a denial of service on Cisco IOS devices by sending a crafted URL to the web UI.
- 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-2025-20327?
CVE-2025-20327 is a high-severity denial of service 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 web UI of Cisco IOS Software could allow an authenticated, remote attacker with low privileges to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper input validation. An attacker could exploit this vulnerability by sending a crafted URL in an HTTP request. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
Weakness: CWE-1287
Which versions are affected by CVE-2025-20327?
It affects 1 product.
Products include Cisco Ios.
How do I fix CVE-2025-20327?
No fix has been published for CVE-2025-20327 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-2025-20327 being exploited?
There is no known exploitation of CVE-2025-20327 in the wild and no public exploit code.
Other vulnerabilities in Cisco Ios
- CVE-2017-12240 Cisco IOS and IOS XE Software DHCP Remote Code Execution
- CVE-2017-3881 Cisco IOS and IOS XE Remote Code Execution
- CVE-2018-0167 Cisco IOS, XR, and XE Software Buffer Overflow
- CVE-2017-6736 Cisco IOS and IOS XE Software SNMP Remote Code Execution
- CVE-2017-6737 Cisco IOS and IOS XE Software SNMP Remote Code Execution
Sources
Also known as GHSA-v2fp-r496-ppm8.