Vulnerability identifier: #VU51769

Vulnerability risk: Medium

CVSSv3.1: 7.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-1446

CWE-ID: CWE-754

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco IOS XE
Operating systems & Components / Operating system
Cisco ASR 1000 Series Aggregation Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cloud Services Router 1000V Series
Hardware solutions / Routers & switches, VoIP, GSM, etc
4000 Series Integrated Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco 1000 Series Integrated Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc

Vendor: Cisco Systems, Inc

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a logic error that occurs when an affected device inspects certain DNS packets. A remote attacker can send specially crafted DNS packets and cause denial of service condition.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Cisco IOS XE: 16.9.5

Cisco ASR 1000 Series Aggregation Services Routers: All versions

Cloud Services Router 1000V Series: All versions

4000 Series Integrated Services Routers: All versions

Cisco 1000 Series Integrated Services Routers: All versions

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-alg-dos-hbBS7SZE

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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.