CVE-2020-12883 : Security Advisory and Response

Buffer over-reads were discovered in the CoAP library in Arm Mbed OS 5.15.3, potentially leading to memory access violations and unintended input processing.

Understanding CVE-2020-12883

What is CVE-2020-12883?

CVE-2020-12883 is a vulnerability in the CoAP library in Arm Mbed OS 5.15.3, specifically related to buffer over-reads during the parsing of CoAP packets.

The Impact of CVE-2020-12883

The vulnerability can result in heap-based or stack-based memory location read access beyond the buffer's intended boundary. This can lead to processing unintended inputs or system memory access violation errors.

Technical Details of CVE-2020-12883

Vulnerability Description

The CoAP parser in Arm Mbed OS 5.15.3 does not properly verify the input packet length against the bytes read, potentially causing memory over-reads.

Affected Systems and Versions

Arm Mbed OS 5.15.3

Exploitation Mechanism

The issue arises due to incorrect calculations in parsing CoAP input, leading to memory access violations.

Mitigation and Prevention

Immediate Steps to Take

Update to the latest version of Arm Mbed OS to patch the vulnerability.
Monitor vendor security advisories for any related updates.

Long-Term Security Practices

Implement secure coding practices to prevent buffer over-read vulnerabilities.
Regularly conduct security assessments and code reviews to identify and address similar issues.

Patching and Updates

Apply patches and updates provided by Arm Mbed OS to mitigate the vulnerability.