ACL Bypass in Cisco IOS XR Software

1) Permissions, Privileges, and Access Controls

EUVDB-ID: #VU80769

Risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2023-20190

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

Exploit availability: No

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to incorrect destination address range encoding in the compression module in the classic access control list (ACL) compression feature. A remote attacker can bypass configured ACL protections and access trusted networks that the device might be protecting.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XR: - - 7.9

CPE2.3

• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.2.0:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.3:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.4:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.5.0:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.6.0:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.7.0:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.8:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xr:7.9:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-comp3acl-vGmp6BQ3

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.