Denial of service in Multiple Cisco Products

1) Buffer Access with Incorrect Length Value

EUVDB-ID: #VU108841

Risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:A/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-2025-20191

CWE-ID: CWE-805 - Buffer Access with Incorrect Length Value

Exploit availability: No

Description

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

The vulnerability exists due to the incorrect handling of DHCPv6 packets in the Switch Integrated Security Features (SISF). A remote attacker on the local network can send a specially crafted DHCPv6 packet and cause a denial of service condition on the target system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Cisco IOS: All versions

Cisco IOS XE: 16.12.1

Cisco NX-OS: 7.0(3)I7(2) - 10.4(3)

Cisco Wireless LAN Controller (WLC) AireOS Software: 8.10.190.0

CPE2.3

• cpe:2.3:o:cisco_systems:cisco_ios:*:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_ios_xe:16.12.1:*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_nx-os:7.0(3)I7(2):*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_nx-os:7.0(3)I7(3):*:*:*:*:*:*:*
• cpe:2.3:o:cisco_systems:cisco_nx-os:7.0(3)I7(5):*:*:*:*:*:*:*
• cpe:2.3:h:cisco_systems:cisco_wireless_lan_controller_wlc_aireos_software:8.10.190.0:*:*:*:*:*:*:*

External links

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sisf-dos-ZGwt4DdY

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the local network (LAN).

Is there known malware, which exploits this vulnerability?

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