CVE-2021-0313 : Security Advisory and Response

In January 2021, CVE-2021-0313 was published concerning a vulnerability in Android operating systems. This CVE can be exploited to cause denial of service without requiring user interaction. The issue lies in the improper input validation in LayoutUtils.cpp, specifically in the isWordBreakAfter function.

Understanding CVE-2021-0313

This section will delve into the specifics of CVE-2021-0313 and its implications.

What is CVE-2021-0313?

The vulnerability identified as CVE-2021-0313 exists within the isWordBreakAfter function of LayoutUtils.cpp. Exploitation of this flaw can lead to a TextView being slowed down or crashed due to the lack of proper input validation. The primary consequence of this vulnerability is the potential for a remote denial of service attack, which can occur without the need for any additional execution privileges. Notably, user interaction is not required for an attacker to exploit this security flaw.

The Impact of CVE-2021-0313

The impact of CVE-2021-0313 is the facilitation of remote denial of service attacks on Android devices running affected versions. By leveraging the vulnerability in LayoutUtils.cpp, threat actors can disrupt the normal operation of TextView, potentially causing system slowdowns or crashes.

Technical Details of CVE-2021-0313

In this section, we will explore the technical aspects of CVE-2021-0313 in more detail.

Vulnerability Description

The vulnerability stems from improper input validation in the isWordBreakAfter function of LayoutUtils.cpp. By exploiting this flaw, attackers can manipulate TextView to slow down or crash, leading to a denial of service condition remotely.

Affected Systems and Versions

The Android operating systems impacted by CVE-2021-0313 include Android-9, Android-10, Android-11, Android-8.0, and Android-8.1. Users of these versions are potentially at risk of falling victim to the described vulnerability.

Exploitation Mechanism

The exploitation of CVE-2021-0313 involves sending specific input that triggers the improper validation in the isWordBreakAfter function. This can cause a TextView to behave abnormally, resulting in a denial of service situation without requiring any user interaction.

Mitigation and Prevention

To safeguard systems against CVE-2021-0313, it is crucial to implement appropriate mitigation strategies and security measures.

Immediate Steps to Take

Immediately following the identification of CVE-2021-0313, users are advised to apply any available security patches or updates provided by the Android operating system. This is essential to prevent potential exploitation of the vulnerability and protect devices from remote denial of service attacks.

Long-Term Security Practices

In the long term, organizations and individuals should prioritize regular software updates and maintenance of their Android devices. Staying up-to-date with the latest security patches helps mitigate the risk of falling victim to known vulnerabilities such as CVE-2021-0313.

Patching and Updates

Ensuring timely installation of security patches and updates released by Android for affected versions is critical. By promptly applying patches, users can address the vulnerability associated with CVE-2021-0313 and enhance the overall security posture of their devices.