Improper access control in Cisco ASR 900 and ASR 920 Series Aggregation Services Routers

1) Improper access control

EUVDB-ID: #VU56832

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-2021-34696

CWE-ID: CWE-284 - Improper Access Control

Exploit availability: No

Description

The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.

The vulnerability exists due to incorrect programming of hardware when an ACL is configured using a method other than the configuration CLI. A remote attacker can bypass an ACL on the affected device.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

ASR 920 Series Aggregation Services Router: All versions

Cisco ASR 9000 Series Aggregation Services Routers: All versions

Cisco IOS XE: 17.3.2

CPE2.3

• cpe:2.3:a:cisco_systems:asr_920_series_aggregation_services_router:*:*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_asr_9000_series_aggregation_services_routers:*:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xe:17.3.2:*:*:*:*:*:*:*

External links

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr900acl-UeEyCxkv

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.