CVE-2021-34714 Multiple Cisco Operating Systems Unidirectional Link Detection Denial of Service Vulnerability
An adjacent attacker can cause a denial of service by sending crafted UDLD packets to Cisco devices with the feature enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2021-34714?
CVE-2021-34714 is a high-severity denial of service vulnerability in Cisco Firepower Extensible Operating System, published on 23 Sep 2021. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. An attacker must have full control of a directly connected device. On Cisco IOS XR devices, the impact is limited to the reload of the UDLD process.
Weakness: CWE-20
Which versions are affected by CVE-2021-34714?
It affects 6 products.
Products include Cisco Firepower Extensible Operating System, Cisco Fxos, Cisco Ios, Cisco Ios Xe, Cisco Ios Xr, Cisco Nx-Os.
How do I fix CVE-2021-34714?
No fix has been published for CVE-2021-34714 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-2021-34714 being exploited?
There is no known exploitation of CVE-2021-34714 in the wild and no public exploit code.
Other vulnerabilities in Cisco Firepower Extensible Operating System
- CVE-2018-0310 Information disclosure in Cisco FXOS and NX-OS unknown
- CVE-2015-6435 Command injection in n/a
- CVE-2021-1368 Memory corruption in Cisco NX-OS Software
- CVE-2020-3456 Cisco FXOS Software Firepower Chassis Manager Cross-Site Request Forgery Vulnerability
- CVE-2020-3172 Cisco FXOS and NX-OS Software Cisco Discovery Protocol Arbitrary Code Execution and Denial of Service Vulnerability
All Cisco Firepower Extensible Operating System vulnerabilities
Sources
Also known as GHSA-wjvw-6gq9-r937.