CVE-2021-31519

An incorrect permission vulnerability in the product installer folders for Trend Micro HouseCall for Home Networks version 5.3.1179 and below could allow an attacker to escalate privileges by placing arbitrary code on a specified folder and have that code be executed by an Administrator who is running a scan. Please note that an attacker must first obtain the ability to execute low-privileged code on the target system to exploit this vulnerability.

Weakness

During installation, installed file permissions are set to allow anyone to modify those files.

Affected Software

Potential Mitigations

• Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
• Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/1.html
• https://cwe.mitre.org/data/definitions/127.html
• https://cwe.mitre.org/data/definitions/81.html

References

• https://helpcenter.trendmicro.com/en-us/article/TMKA-10310
• https://www.zerodayinitiative.com/advisories/ZDI-21-475/