Vulnerability identifier: #VU73988

Vulnerability risk: High

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-2023-20027

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco IOS XE
Operating systems & Components / Operating system
Cisco 1000 Series Integrated Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
4000 Series Integrated Services Routers
Hardware solutions / Routers & switches, VoIP, GSM, etc
Catalyst 8000V Edge Software
Hardware solutions / Routers & switches, VoIP, GSM, etc
Catalyst 8200 Series Edge Platforms
Hardware solutions / Routers & switches, VoIP, GSM, etc
Catalyst 8300 Series Edge Platforms
Hardware solutions / Routers & switches, VoIP, GSM, etc
Catalyst 8500L Series Edge Platforms
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cloud Services Router 1000V Series
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 improper reassembly of large packets in the implementation of the IPv4 Virtual Fragmentation Reassembly (VFR) feature. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XE: 17.3.3

Cisco 1000 Series Integrated Services Routers: All versions

4000 Series Integrated Services Routers: All versions

Catalyst 8000V Edge Software: All versions

Catalyst 8200 Series Edge Platforms: All versions

Catalyst 8300 Series Edge Platforms: All versions

Catalyst 8500L Series Edge Platforms: All versions

Cloud Services Router 1000V Series: All versions

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External links
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ipv4-vfr-dos-CXxtFacb

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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.