CVE-2021-34713: high-severity vulnerability in Cisco IOS XR Software
Cisco IOS XR Software for ASR 9000 Series Routers Denial of Service Vulnerability
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.4epss 0.4%
A vulnerability in the Layer 2 punt code of Cisco IOS XR Software running on Cisco ASR 9000 Series Aggregation Services Routers could allow an unauthenticated, adjacent attacker to cause the affected line card to reboot. This vulnerability is due to incorrect handling of specific Ethernet frames that cause a spin loop that can make the network processors unresponsive. An attacker could exploit this vulnerability by sending specific types of Ethernet frames on the segment where the affected line cards are attached. A successful exploit could allow the attacker to cause the affected line card to reboot.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Affected products
Cisco · Cisco IOS XR SoftwareRelated CVEs — Cisco IOS XR Software
In the same product, most dangerous first.
CVE-2020-3118HIGHCisco IOS XR Software Cisco Discovery Protocol Format String VulnerabilityEPSS 11.7%KEVCVE-2022-20821MEDIUMCisco IOS XR Software Health Check Open Port VulnerabilityEPSS 11.5%KEVCVE-2020-3566HIGHCisco IOS XR Software DVMRP Memory Exhaustion VulnerabilityEPSS 3.7%KEVCVE-2020-3569HIGHCisco IOS XR Software DVMRP Memory Exhaustion VulnerabilitiesEPSS 3.3%KEVCVE-2025-20363CRITICALCVE-2025-20363EPSS 7.2%CVE-2020-3284HIGHCisco IOS XR Software Enhanced Preboot eXecution Environment Unsigned Code Execution VulnerabilityEPSS 2.9%