CVE-2021-3405 : What You Need to Know

A heap overflow vulnerability was discovered in libebml before version 1.4.2, specifically in the implementation of EbmlString::ReadData and EbmlUnicodeString::ReadData. This flaw is identified as CWE-787.

Understanding CVE-2021-3405

This section details the impact, technical aspects, and mitigation strategies related to CVE-2021-3405.

What is CVE-2021-3405?

The vulnerability CVE-2021-3405 affects the libebml library before version 1.4.2 due to a heap overflow bug present in the EbmlString::ReadData and EbmlUnicodeString::ReadData implementation.

The Impact of CVE-2021-3405

An attacker exploiting this vulnerability could potentially execute arbitrary code or cause a denial of service (DoS) condition on systems utilizing the vulnerable versions of libebml.

Technical Details of CVE-2021-3405

This section provides more insight into the vulnerability.

Vulnerability Description

A heap overflow bug exists in the implementation of EbmlString::ReadData and EbmlUnicodeString::ReadData in libebml versions before 1.4.2.

Affected Systems and Versions

Systems that have libebml installed before version 1.4.2 are vulnerable to CVE-2021-3405.

Exploitation Mechanism

The vulnerability can be exploited by an attacker crafting a specially designed file or content to trigger the heap overflow bug and potentially execute malicious code.

Mitigation and Prevention

To safeguard systems from CVE-2021-3405, immediate steps and long-term security practices are crucial.

Immediate Steps to Take

Update libebml to version 1.4.2 or later to mitigate the vulnerability.
Consider implementing file/content scanning mechanisms to detect and block malformed inputs.

Long-Term Security Practices

Regularly update software components to patch known vulnerabilities.
Conduct security assessments and code reviews to identify and address potential security flaws.

Patching and Updates

Stay informed about security advisories and apply patches promptly to ensure the security of the systems.