CVE-2018-5996 Explained : Impact and Mitigation

7-Zip and p7zip versions prior to 18.00 are vulnerable to memory corruptions due to inadequate exception handling in the NCompress::NRar3::CDecoder::Code method. This can lead to denial of service or arbitrary code execution through specially-crafted RAR archives.

Understanding CVE-2018-5996

This CVE involves a vulnerability in 7-Zip and p7zip that allows remote attackers to exploit memory corruptions in the PPMd code.

What is CVE-2018-5996?

The NCompress::NRar3::CDecoder::Code method in 7-Zip versions before 18.00 and p7zip lacks proper exception handling, leading to memory corruptions in the PPMd code. Attackers can trigger a denial of service or execute arbitrary code using a malicious RAR archive.

The Impact of CVE-2018-5996

Remote attackers can exploit this vulnerability to cause a denial of service (segmentation fault) or execute arbitrary code.

Technical Details of CVE-2018-5996

7-Zip and p7zip versions prior to 18.00 are affected by this vulnerability.

Vulnerability Description

Insufficient exception handling in the NCompress::NRar3::CDecoder::Code method of 7-Zip and p7zip can result in memory corruptions, enabling attackers to execute arbitrary code.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: All versions prior to 18.00

Exploitation Mechanism

Attackers can exploit this vulnerability by using a specially-crafted RAR archive to trigger memory corruptions in the PPMd code.

Mitigation and Prevention

To address CVE-2018-5996, follow these steps:

Immediate Steps to Take

Update 7-Zip and p7zip to version 18.00 or newer.
Avoid opening RAR archives from untrusted sources.

Long-Term Security Practices

Regularly update software to the latest versions to patch known vulnerabilities.
Implement network security measures to prevent remote exploitation.
Educate users on safe browsing habits and the risks of opening files from unknown sources.

Patching and Updates

Apply patches provided by the software vendors promptly to mitigate the vulnerability.