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CVE-2020-3479

HIGHCVSS 7.5/10EPSS 1.10%

Last modified

CVE-2020-3479 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. A vulnerability in the implementation of Multiprotocol Border Gateway Protocol (MP-BGP) for the Layer 2 VPN (L2VPN) Ethernet VPN (EVPN) address family in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of Border Gateway Protocol (BGP) update messages that contain crafted EVPN attributes. EPSS estimates a 1.10% chance of exploitation in the next 30 days.

Description

A vulnerability in the implementation of Multiprotocol Border Gateway Protocol (MP-BGP) for the Layer 2 VPN (L2VPN) Ethernet VPN (EVPN) address family in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of Border Gateway Protocol (BGP) update messages that contain crafted EVPN attributes. An attacker could exploit this vulnerability by sending BGP update messages with specific, malformed attributes to an affected device. A successful exploit could allow the attacker to cause an affected device to crash, resulting in a DoS condition.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
1.10%

61.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
CiscoIosAll versions
CiscoIos XeAll versions

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2020-3479?
A vulnerability in the implementation of Multiprotocol Border Gateway Protocol (MP-BGP) for the Layer 2 VPN (L2VPN) Ethernet VPN (EVPN) address family in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of Border Gateway Protocol (BGP) update messages that contain crafted EVPN attributes. An attacker could exploit this vulnerability by sending BGP update messages with specific, malformed attributes to an affected device. A successful exploit could allow the attacker to cause an affected device to crash, resulting in a DoS condition.
How severe is CVE-2020-3479?
CVE-2020-3479 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.10% probability of exploitation in the next 30 days.
How do I fix CVE-2020-3479?
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-2020-3479?

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

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Source: NVD / NIST