CVE-2021-4048 : Security Advisory and Response

An out-of-bounds read flaw was found in the CLARRV, DLARRV, SLARRV, and ZLARRV functions in lapack through version 3.10.0, as also used in OpenBLAS before version 0.3.18. Specially crafted inputs passed to these functions could cause an application using lapack to crash or possibly disclose portions of its memory.

Understanding CVE-2021-4048

This CVE-2021-4048 vulnerability involves an out-of-bounds read flaw in certain functions of lapack through version 3.10.0, which could potentially lead to a denial of service or memory exposure.

What is CVE-2021-4048?

CVE-2021-4048 is an out-of-bounds read vulnerability identified in lapack through version 3.10.0, impacting the CLARRV, DLARRV, SLARRV, and ZLARRV functions. It can be exploited by providing specially crafted inputs, resulting in a potential application crash or information disclosure.

The Impact of CVE-2021-4048

This vulnerability can be exploited by malicious actors to crash an application using lapack or disclose sensitive information stored in its memory. It poses a significant risk to the integrity and confidentiality of affected systems.

Technical Details of CVE-2021-4048

The following technical details outline the specific aspects of CVE-2021-4048:

Vulnerability Description

The vulnerability involves an out-of-bounds read flaw in lapack through version 3.10.0, affecting certain functions and potentially leading to memory disclosure or application crashes.

Affected Systems and Versions

Systems using lapack through version 3.10.0 and OpenBLAS before version 0.3.18 are susceptible to this vulnerability.

Exploitation Mechanism

By providing specially crafted inputs to the CLARRV, DLARRV, SLARRV, and ZLARRV functions, threat actors can trigger the vulnerability, causing the application to crash or exposing sensitive memory contents.

Mitigation and Prevention

To mitigate the risks associated with CVE-2021-4048, users and organizations are advised to take the following steps:

Immediate Steps to Take

Update lapack to version 3.10.0 or later to patch the vulnerability.
Monitor for any unusual activities on systems that could indicate exploitation attempts.

Long-Term Security Practices

Implement robust input validation mechanisms to prevent malicious inputs from triggering vulnerabilities.
Regularly update software and libraries to apply security patches and enhancements.

Patching and Updates

Stay informed about security advisories and updates released by lapack and OpenBLAS to address known vulnerabilities and improve overall system security.