CVE-2020-5235 : What You Need to Know

Nanopb before versions 0.4.1, 0.3.9.5, and 0.2.9.4 is affected by a potentially exploitable out-of-memory condition when compiled with PB_ENABLE_MALLOC.

Understanding CVE-2020-5235

This CVE identifies a vulnerability in Nanopb that could lead to memory corruption and potential exploitation.

What is CVE-2020-5235?

The vulnerability in Nanopb versions before 0.4.1, 0.3.9.5, and 0.2.9.4 allows for an out-of-memory condition when realloc() runs out of memory during array expansion, potentially leading to crashes or memory corruption.

The Impact of CVE-2020-5235

The impact of this vulnerability is rated as MEDIUM severity with a CVSS base score of 6.5. It requires a high attack complexity but does not need privileges for exploitation.

Technical Details of CVE-2020-5235

Nanopb vulnerability details and affected systems.

Vulnerability Description

Nanopb before 0.4.1, 0.3.9.5, and 0.2.9.4 are prone to out-of-memory conditions when compiled with PB_ENABLE_MALLOC.

Affected Systems and Versions

Nanopb versions < 0.2.9.4
Nanopb versions >= 0.3.0, < 0.3.9.5
Nanopb versions >= 0.4.0, < 0.4.1

Exploitation Mechanism

When realloc() runs out of memory during array expansion, Nanopb may call

free()

on uninitialized memory, leading to potential crashes or memory corruption.

Mitigation and Prevention

Steps to mitigate and prevent the CVE-2020-5235 vulnerability.

Immediate Steps to Take

Update Nanopb to version 0.4.1, 0.3.9.5, or 0.2.9.4 to address the out-of-memory issue.
Avoid compiling Nanopb with PB_ENABLE_MALLOC if possible.

Long-Term Security Practices

Regularly monitor for security advisories and updates from Nanopb.
Implement secure coding practices to prevent memory-related vulnerabilities.

Patching and Updates

Apply patches provided by Nanopb promptly to address known vulnerabilities and improve system security.