CVE-2021-40154 : Exploit Details and Defense Strategies
Learn about CVE-2021-40154, a buffer over-read vulnerability on NXP LPC55S69 devices before A3, allowing disclosure of protected flash memory. Find mitigation steps and impacts.
NXP LPC55S69 devices before A3 are vulnerable to a buffer over-read via a crafted wlength value in a GET Descriptor Configuration request when using USB In-System Programming (ISP) mode. This leads to the disclosure of protected flash memory.
Understanding CVE-2021-40154
This CVE highlights a specific vulnerability in NXP LPC55S69 devices that can be exploited under certain conditions.
What is CVE-2021-40154?
CVE-2021-40154 is a buffer over-read vulnerability on NXP LPC55S69 devices that can be triggered through a GET Descriptor Configuration request in USB ISP mode.
The Impact of CVE-2021-40154
The vulnerability has the following impact based on the CVSS v3.1 metrics:
- Base Score: 6.1 (Medium)
- Attack Vector: Local
- Attack Complexity: Low
- Privileges Required: Low
- User Interaction: None
- Confidentiality Impact: High
- Integrity Impact: None
- Availability Impact: Low
- Scope: Unchanged
Technical Details of CVE-2021-40154
The technical aspects of the CVE provide deeper insight into the vulnerability and its implications.
Vulnerability Description
The vulnerability involves a buffer over-read through a specific request in USB ISP mode on affected devices, resulting in the exposure of protected flash memory.
Affected Systems and Versions
- Affected Product: NXP LPC55S69 devices before A3
- Affected Version: Not specified
Exploitation Mechanism
The vulnerability is exploited by sending a crafted wlength value in a GET Descriptor Configuration request while using USB ISP mode, leading to the buffer over-read and disclosure of flash memory.
Mitigation and Prevention
Mitigation strategies can help in reducing the risk associated with CVE-2021-40154.
Immediate Steps to Take
- Implement vendor-supplied patches or updates immediately.
- Restrict physical access to vulnerable devices.
- Monitor network traffic for any suspicious activities.
Long-Term Security Practices
- Regularly update firmware and software to patch known vulnerabilities.
- Perform security assessments and penetration testing regularly.
Patching and Updates
- Apply all relevant security patches released by NXP for the affected devices.