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CVE-2021-34767

HIGHCVSS 7.4/10EPSS 0.76%

Last modified

CVE-2021-34767 is a high-severity vulnerability rated 7.4/10 on the CVSS scale. A vulnerability in IPv6 traffic processing of Cisco IOS XE Wireless Controller Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a Layer 2 (L2) loop in a configured VLAN, resulting in a denial of service (DoS) condition for that VLAN. The vulnerability is due to a logic error when processing specific link-local IPv6 traffic. EPSS estimates a 0.76% chance of exploitation in the next 30 days.

Description

A vulnerability in IPv6 traffic processing of Cisco IOS XE Wireless Controller Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a Layer 2 (L2) loop in a configured VLAN, resulting in a denial of service (DoS) condition for that VLAN. The vulnerability is due to a logic error when processing specific link-local IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that would flow inbound through the wired interface of an affected device. A successful exploit could allow the attacker to cause traffic drops in the affected VLAN, thus triggering the DoS condition.

Metrics

CVSS 3.1
7.4/10

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

EPSS Probability
0.76%

50.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoIos XeAll versions
CiscoIos Xe3.15.1xbs
CiscoIos Xe3.15.2xbs
CiscoIos Xe16.7.1
CiscoIos Xe16.7.1a
CiscoIos Xe16.7.1b
CiscoIos Xe16.7.2
CiscoIos Xe16.7.3
CiscoIos Xe16.7.4
CiscoIos Xe16.8.1
CiscoIos Xe16.8.1a
CiscoIos Xe16.8.1b
CiscoIos Xe16.8.1c
CiscoIos Xe16.8.1d
CiscoIos Xe16.8.1e
CiscoIos Xe16.8.1s
CiscoIos Xe16.8.2
CiscoIos Xe16.8.3
CiscoIos Xe16.9.1
CiscoIos Xe16.9.1a
CiscoIos Xe16.9.1b
CiscoIos Xe16.9.1c
CiscoIos Xe16.9.1d
CiscoIos Xe16.9.1s
CiscoIos Xe16.9.2
CiscoIos Xe16.9.2a
CiscoIos Xe16.9.2s
CiscoIos Xe16.9.3
CiscoIos Xe16.9.3a
CiscoIos Xe16.9.3h
CiscoIos Xe16.9.3s
CiscoIos Xe16.9.4
CiscoIos Xe16.9.4c
CiscoIos Xe16.9.5
CiscoIos Xe16.9.5f
CiscoIos Xe16.9.6
CiscoIos Xe16.9.7
CiscoIos Xe16.10.1
CiscoIos Xe16.10.1a
CiscoIos Xe16.10.1b
CiscoIos Xe16.10.1c
CiscoIos Xe16.10.1d
CiscoIos Xe16.10.1e
CiscoIos Xe16.10.1f
CiscoIos Xe16.10.1g
CiscoIos Xe16.10.1s
CiscoIos Xe16.10.2
CiscoIos Xe16.10.3
CiscoIos Xe16.11.1
CiscoIos Xe16.11.1a

Showing 50 of 93 affected configurations. See NVD for the full list.

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2021-34767?
A vulnerability in IPv6 traffic processing of Cisco IOS XE Wireless Controller Software for Cisco Catalyst 9000 Family Wireless Controllers could allow an unauthenticated, adjacent attacker to cause a Layer 2 (L2) loop in a configured VLAN, resulting in a denial of service (DoS) condition for that VLAN. The vulnerability is due to a logic error when processing specific link-local IPv6 traffic. An attacker could exploit this vulnerability by sending a crafted IPv6 packet that would flow inbound through the wired interface of an affected device. A successful exploit could allow the attacker to cause traffic drops in the affected VLAN, thus triggering the DoS condition.
How severe is CVE-2021-34767?
CVE-2021-34767 has a CVSS score of 7.4/10 (HIGH severity). The EPSS model estimates a 0.76% probability of exploitation in the next 30 days.
How do I fix CVE-2021-34767?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34767?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST