CVE-2019-12672

A vulnerability in the filesystem of Cisco IOS XE Software could allow an authenticated, local attacker with physical access to an affected device to execute arbitrary code on the underlying operating system (OS) with root privileges. The vulnerability is due to insufficient file location validation. An attacker could exploit this vulnerability by placing code in a specific format on a USB device and inserting it into an affected Cisco device. A successful exploit could allow the attacker to execute the code with root privileges on the underlying OS of the affected device.

Weakness

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected Software

Potential Mitigations

• Follow the principle of least privilege when assigning access rights to entities in a software system.
• Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/132.html
• https://cwe.mitre.org/data/definitions/17.html
• https://cwe.mitre.org/data/definitions/35.html
• https://cwe.mitre.org/data/definitions/76.html

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190925-iosxe-codeexec