#VU56854 NULL pointer dereference in Cisco Systems, Inc products - CVE-2021-34768

Vulnerability identifier: #VU56854

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-34768

CWE-ID: CWE-476

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Cisco IOS XE
Operating systems & Components / Operating system
Catalyst 9800 Embedded Wireless Controller
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Catalyst 9800 Series Wireless Controllers
Hardware solutions / Routers & switches, VoIP, GSM, etc
Catalyst 9800-CL Wireless Controllers for Cloud
Hardware solutions / Routers & switches, VoIP, GSM, etc
Cisco Embedded Wireless Controller Software for Catalyst Access Points
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 NULL pointer dereference error in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol. A remote attacker can pass specially crafted data to the application and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Cisco IOS XE: 17.3.1, 17.4.1, 17.5.1

Catalyst 9800 Embedded Wireless Controller: All versions

Cisco Catalyst 9800 Series Wireless Controllers: All versions

Catalyst 9800-CL Wireless Controllers for Cloud: All versions

Cisco Embedded Wireless Controller Software for Catalyst Access Points: All versions

---

External links
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ewlc-capwap-dos-gmNjdKOY

---

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.