CVE-2018-1000877 : Vulnerability Insights and Analysis

A Double Free vulnerability in the RAR decoder module of libarchive version v3.1.0 onwards can lead to a Crash or Denial-of-Service (DoS) situation when a specially crafted RAR archive is opened.

Understanding CVE-2018-1000877

This CVE involves a vulnerability in the RAR decoder module of libarchive version v3.1.0 onwards.

What is CVE-2018-1000877?

Starting from commit 416694915449219d505531b1096384f3237dd6cc of libarchive version v3.1.0 onwards, a Double Free vulnerability exists in the RAR decoder module, leading to a potential Crash or DoS situation.

The Impact of CVE-2018-1000877

The vulnerability can be exploited by opening a specifically crafted RAR archive, potentially resulting in a Crash or Denial-of-Service (DoS) scenario.

Technical Details of CVE-2018-1000877

This section provides detailed technical information about the CVE.

Vulnerability Description

The vulnerability is observed in the parse_codes() function of the RAR decoder module in libarchive, where the realloc() function reallocates rar->lzss.window with new_size = 0, leading to the Double Free vulnerability.

Affected Systems and Versions

Affected versions: libarchive v3.1.0 onwards
Systems using libarchive with the RAR decoder module

Exploitation Mechanism

Exploitation requires the victim to open a specifically crafted RAR archive

Mitigation and Prevention

Protecting systems from CVE-2018-1000877 involves immediate steps and long-term security practices.

Immediate Steps to Take

Apply security updates and patches promptly
Avoid opening RAR archives from untrusted or unknown sources
Implement file type and content scanning for archives

Long-Term Security Practices

Regularly update software and libraries
Conduct security audits and vulnerability assessments
Educate users on safe browsing and file handling practices

Patching and Updates

Update libarchive to the latest patched version
Monitor vendor security advisories for relevant updates