Vulnerability Name:

CVE-2021-1389 (CCN-196137)

Assigned:2020-11-13
Published:2021-02-03
Updated:2022-09-20
Summary: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.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): Low
Integrity (I): Low
Availibility (A): None
5.8 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N)
5.1 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Changed
Impact Metrics:Confidentiality (C): None
Integrity (I): Low
Availibility (A): None
CVSS v2 Severity:6.4 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:P/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): Partial
Integrity (I): Partial
Availibility (A): None
5.0 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:N)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): None
Vulnerability Type:CWE-Other
Vulnerability Consequences:Bypass Security
References:Source: MITRE
Type: CNA
CVE-2021-1389

Source: XF
Type: UNKNOWN
cisco-cve20211389-sec-bypass(196137)

Source: CCN
Type: Cisco Security Advisory cisco-sa-ipv6-acl-CHgdYk8j
Cisco IOS XR and Cisco NX-OS Software IPv6 Access Control List Bypass Vulnerability

Source: CISCO
Type: Vendor Advisory
20210203 Cisco IOS XR and Cisco NX-OS Software IPv6 Access Control List Bypass Vulnerability

Vulnerable Configuration:Configuration 1:
  • cpe:/o:cisco:ios_xr:*:*:*:*:*:*:*:* (Version < 6.6.3)
  • OR cpe:/o:cisco:ios_xr:7.2.0:*:*:*:*:*:*:*
  • OR cpe:/o:cisco:ios_xr:7.1.0:*:*:*:*:*:*:*
  • AND
  • cpe:/h:cisco:ncs_540:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_560:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_5501:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_5501-se:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_5502:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_5502-se:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_5508:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:ncs_5516:-:*:*:*:*:*:*:*

    • Configuration 2:
  • cpe:/o:cisco:nx-os:-:*:*:*:*:*:*:*
  • AND
  • cpe:/h:cisco:nexus_9500_r:-:*:*:*:*:*:*:*
  • OR cpe:/h:cisco:nexus_3600:-:*:*:*:*:*:*:*

    • Configuration CCN 1:
  • cpe:/o:cisco:ios_xr:-:*:*:*:*:*:*:*
  • OR cpe:/a:cisco:nx-os:*:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    cisco ios xr *
    cisco ios xr 7.2.0
    cisco ios xr 7.1.0
    cisco ncs 540 -
    cisco ncs 560 -
    cisco ncs 5501 -
    cisco ncs 5501-se -
    cisco ncs 5502 -
    cisco ncs 5502-se -
    cisco ncs 5508 -
    cisco ncs 5516 -
    cisco nx-os -
    cisco nexus 9500 r -
    cisco nexus 3600 -
    cisco ios xr -
    cisco nx-os *