CVE-2021-1389 : A vulnerability in the IPv6 traffic processing of Cisco IOS XR Software and Cisc

A vulnerability in the IPv6 traffic processing of Cisco IOS XR Software and Cisco NX-OS Software for certain Cisco devices could allow an unauthenticated, remote attacker to bypass an IPv6 access control list (ACL) that is configured for an interface of an affected device. The vulnerability is due to improper processing of IPv6 traffic that is sent through an affected device. An attacker could exploit this vulnerability by sending crafted IPv6 packets that traverse the affected device. A successful exploit could allow the attacker to access resources that would typically be protected by the interface ACL.

Published 2021-02-04 17:15:19

Updated 2022-09-20 17:03:08

Source Cisco Systems, Inc.

View at NVD, CVE.org

Vulnerability category: BypassGain privilege

Products affected by CVE-2021-1389

Cisco » Ios Xr
Versions before (<) 6.6.3
cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Ncs 540 » Version: N/A
When used together with: Cisco » Ncs 5501 » Version: N/A
When used together with: Cisco » Ncs 5501-se » Version: N/A
When used together with: Cisco » Ncs 5502 » Version: N/A
When used together with: Cisco » Ncs 5502-se » Version: N/A
When used together with: Cisco » Ncs 5508 » Version: N/A
When used together with: Cisco » Ncs 5516 » Version: N/A
When used together with: Cisco » Ncs 560 » Version: N/A
Cisco » Ios Xr » Version: 7.1.0
cpe:2.3:o:cisco:ios_xr:7.1.0:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Ncs 540 » Version: N/A
When used together with: Cisco » Ncs 5501 » Version: N/A
When used together with: Cisco » Ncs 5501-se » Version: N/A
When used together with: Cisco » Ncs 5502 » Version: N/A
When used together with: Cisco » Ncs 5502-se » Version: N/A
When used together with: Cisco » Ncs 5508 » Version: N/A
When used together with: Cisco » Ncs 5516 » Version: N/A
When used together with: Cisco » Ncs 560 » Version: N/A
Cisco » Ios Xr » Version: 7.2.0
cpe:2.3:o:cisco:ios_xr:7.2.0:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Ncs 540 » Version: N/A
When used together with: Cisco » Ncs 5501 » Version: N/A
When used together with: Cisco » Ncs 5501-se » Version: N/A
When used together with: Cisco » Ncs 5502 » Version: N/A
When used together with: Cisco » Ncs 5502-se » Version: N/A
When used together with: Cisco » Ncs 5508 » Version: N/A
When used together with: Cisco » Ncs 5516 » Version: N/A
When used together with: Cisco » Ncs 560 » Version: N/A
Cisco » Nx-os » Version: N/A
cpe:2.3:o:cisco:nx-os:-:*:*:*:*:*:*:*
Matching versions
When used together with: Cisco » Nexus 3600 » Version: N/A
When used together with: Cisco » Nexus 9500 R » Version: N/A

Exploit prediction scoring system (EPSS) score for CVE-2021-1389

EPSS FAQ

0.28%

Probability of exploitation activity in the next 30 days EPSS Score History

~ 49 %

Percentile, the proportion of vulnerabilities that are scored at or less

CVSS scores for CVE-2021-1389

Base Score	Base Severity	CVSS Vector	Exploitability Score	Impact Score	Score Source
6.4	MEDIUM	AV:N/AC:L/Au:N/C:P/I:P/A:N	10.0	4.9	NIST
Access Vector: Network Access Complexity: Low Authentication: None Confidentiality Impact: Partial Integrity Impact: Partial Availability Impact: None
5.8	MEDIUM	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N	3.9	1.4	Cisco Systems, Inc.
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Changed Confidentiality: None Integrity: Low Availability: None
6.5	MEDIUM	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N	3.9	2.5	NIST
Attack Vector: Network Attack Complexity: Low Privileges Required: None User Interaction: None Scope: Unchanged Confidentiality: Low Integrity: Low Availability: None

CWE ids for CVE-2021-1389

CWE-284 Improper Access Control

The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.

Assigned by: ykramarz@cisco.com (Secondary)

References for CVE-2021-1389

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv6-acl-CHgdYk8j

Cisco IOS XR and Cisco NX-OS Software IPv6 Access Control List Bypass Vulnerability
Vendor Advisory

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Vulnerability Details : CVE-2021-1389

Products affected by CVE-2021-1389

Exploit prediction scoring system (EPSS) score for CVE-2021-1389

CVSS scores for CVE-2021-1389

CWE ids for CVE-2021-1389

References for CVE-2021-1389