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CVE-2023-20187

A vulnerability in the Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation…

High8.6EPSS 0.88%
Published
Updated
Reserved
Assigned by
cisco

Description

A vulnerability in the Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect handling of certain IPv6 multicast packets when they are fanned out more than seven times on an affected device. An attacker could exploit this vulnerability by sending a specific IPv6 multicast or IPv6 multicast VPN (MVPNv6) packet through the affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a DoS condition.

Scores

CVSS scores of CVE-2023-20187, by who scored it
Scored byCVSSScoreVector
ciscoCNA (assigner)3.1High8.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVDNVD · Modified3.1High7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (exploitation in 30 days)
0.88% · top 41% of all CVEs (6 Nov 2026)
Loading the EPSS history…

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.6.

Weakness

Affected products

  • Cisco · Cisco IOS XE Software

    • affected 3.7.1S
    • affected 3.7.2S
    • affected 3.7.3S
    • affected 3.7.4S
    • affected 3.7.5S
    • affected 3.7.6S
    • affected 3.7.7S
    • affected 3.7.2tS
    • affected 3.8.0S
    • affected 3.8.1S
    • affected 3.8.2S
    • affected 3.9.1S
    • affected 3.9.0S
    • affected 3.9.2S
    • affected 3.10.0S
    • affected 3.10.1S
    • affected 3.10.2S
    • affected 3.10.3S
    • affected 3.10.4S
    • affected 3.10.5S
    • affected 3.10.6S
    • affected 3.10.7S
    • affected 3.10.1xbS
    • affected 3.10.8S
    • affected 3.10.8aS
    • affected 3.10.9S
    • affected 3.10.10S
    • affected 3.11.1S
    • affected 3.11.2S
    • affected 3.11.0S
    • affected 3.11.3S
    • affected 3.11.4S
    • affected 3.12.0S
    • affected 3.12.1S
    • affected 3.12.2S
    • affected 3.12.3S
    • affected 3.12.4S
    • affected 3.13.0S
    • affected 3.13.1S
    • affected 3.13.2S
    • and 163 more

What to do

Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References (1)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

CVE-2023-20187 badge
[![CVE-2023-20187](https://trackcve.app/badge/CVE-2023-20187.svg)](https://trackcve.app/cve/CVE-2023-20187)

Record last updated .