Improper input validation in Cisco iOS
CVE-2021-34714
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.
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
EPSS: 0.004 (32.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.4 (High). Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.
Affected products
Weakness classification (CWE)
References
- psirt@cisco.com (x_refsource_CISCO, vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-34714?
- CVE-2021-34714 is a high-severity vulnerability in Cisco iOS, classified under Improper Input Validation. CVSS score: 7.4/10. Published 2021-09-23.
- How severe is CVE-2021-34714?
- High severity. CVSS v3 base score is 7.4 out of 10.