Affected Version(s)
| Product | Affected Version(s) | Platform | Language(s) |
|---|---|---|---|
| Worry-Free Business Security | WFBS 10 SP1 | Windows macOS (client) | English |
| Services (WFBSS) | Windows macOS (client) | English |
Solution
Trend Micro has released the following solutions to address the issue:
| Product | Updated version | Notes | Platform | Availability |
|---|---|---|---|---|
| WFBS | 10 SP1 b2228 | Readme | Windows | Now Available |
| macOS Patch | macOS | Available on ActiveUpdate | ||
| WFBSS* | 6.7.1374 / 14.2.1194 | Windows | Now Available | |
| macOS Agent 3.5.1396 | macOS | Now Available |
These are the minimum recommended version(s) of the patches and/or builds required to address the issue. Trend Micro highly encourages customers to obtain the latest version of the product if there is a newer one available than the one listed in this bulletin.
*For Worry-Free Business Security Services (WFBSS), agent upgrade and hot fix deployment can be controlled under Configure Policy > Agent Configurations > Privileges and Other Settings > Other Settings.
Customers are encouraged to visit Trend Micro’s Download Center to obtain prerequisite software (such as Service Packs) before applying any of the solutions above.
Vulnerability Details
CVE-2020-24556: Hard Link Privilege Escalation Vulnerability (Windows)
CVSSv3: 7.8: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
A vulnerability in Trend Micro Worry-Free Business Security and Worry-Free Business Security Services on Microsoft Windows may allow an attacker to create a hard link to any file on the system, which then could be manipulated to gain a privilege escalation and code execution.
An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
Please note that version 1909 (OS Build 18363.719) of Microsoft Windows 10 mitigates hard links, but previous versions are affected.
CVE-2020-24557: Improper Access Control Privilege Escalation
CVSSv3: 7.8: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
A vulnerability in Trend Micro Worry-Free Business Security on Microsoft Windows may allow an attacker to manipulate a particular product folder to disable the security temporarily, abuse a specific Windows function and attain privilege escalation.
An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
Please note that Worry-Free Business Security Services (WFBSS) is not affected by this vulnerability. In addition, version 1909 (OS Build 18363.719) of Microsoft Windows 10 mitigates hard links, but previous versions are affected.
CVE-2020-24558: Out-of-Bounds Read Information Disclosure
CVSSv3: 5.5: AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
A vulnerability in an Trend Micro Worry-Free Business Security and Worry-Free Business Security Services dll may allow an attacker to manipulate it to cause an out-of-bounds read that crashes multiple processes in the product.
An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
Please note that an earlier WFBSS hotfix (6.7.1304 / 14.2.1165) resolves this particular issue; however, it is recommended that customers ensure they are on the latest version to address all the vulnerabilities in this bulletin.
CVE-2020-24559: Hard Link Privilege Escalation Vulnerability (macOS)
CVSSv3: 7.8: AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
A vulnerability in Trend Micro Worry-Free Business Security and Worry-Free Business Security Services on macOS may allow an attacker to manipulate a certain binary to load and run a script from a user-writable folder, which then would allow them to execute arbitrary code as root.
An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability.
Please note that the updated macOS client for WFBS is available via Trend Micro's ActiveUpdate.
Mitigating Factors
Exploiting these type of vulnerabilities generally require that an attacker has access (physical or remote) to a vulnerable machine. In addition to timely application of patches and updated solutions, customers are also advised to review remote access to critical systems and ensure policies and perimeter security is up-to-date.
Newer versions of the operating system (e.g. Windows 10) may protect against some vulnerabilities such as hard link privilege escalations.
However, even though an exploit may require several specific conditions to be met, Trend Micro strongly encourages customers to update to the latest builds as soon as possible.
Acknowledgement
Trend Micro would like to thank the following individuals for responsibly disclosing these issues and working with Trend Micro to help protect our customers:
- @Kharosx0 working with Trend Micro's Zero Day Initiative
External Reference(s)
- ZDI-20-1093
- ZDI-20-1094
- ZDI-20-1095
- ZDI-20-1096