CVE-2020-9308 : Security Advisory and Response

This CVE involves a vulnerability in libarchive that could lead to a SIGSEGV or other unspecified impacts due to attempting to unpack a RAR5 file with an invalid or corrupted header.

Understanding CVE-2020-9308

This vulnerability affects the unpacking process of RAR5 files in libarchive, potentially resulting in a denial of service or other adverse effects.

What is CVE-2020-9308?

The vulnerability in libarchive before version 3.4.2 arises from the mishandling of RAR5 file headers, specifically when encountering invalid or corrupted headers.

The Impact of CVE-2020-9308

The exploitation of this vulnerability can lead to a SIGSEGV (Segmentation Fault) or other unspecified impacts, potentially causing a denial of service or arbitrary code execution.

Technical Details of CVE-2020-9308

This section delves into the specific technical aspects of the CVE.

Vulnerability Description

The issue lies in the 'archive_read_support_format_rar5.c' file in libarchive, where unpacking a RAR5 file with a zero-sized or corrupted header triggers the vulnerability.

Affected Systems and Versions

The vulnerability affects libarchive versions prior to 3.4.2.

Exploitation Mechanism

Attackers can exploit this vulnerability by crafting a specially designed RAR5 file with an invalid or corrupted header, leading to the potential for a SIGSEGV or other adverse effects.

Mitigation and Prevention

To address CVE-2020-9308, it is crucial to implement immediate steps and adopt long-term security practices.

Immediate Steps to Take

Update libarchive to version 3.4.2 or newer to mitigate the vulnerability.
Avoid opening RAR5 files from untrusted or unknown sources.

Long-Term Security Practices

Regularly update software and libraries to the latest versions to patch known vulnerabilities.
Employ robust security measures such as network segmentation and access controls to reduce the attack surface.

Patching and Updates

Stay informed about security advisories and promptly apply patches released by the software vendor to address vulnerabilities.