CVE-2018-18459 : Exploit Details and Defense Strategies

Xpdf 4.00 is vulnerable to a denial of service attack due to a NULL pointer dereference in the DCTStream::getBlock function in the Stream.cc file. Attackers can exploit this by using a specially crafted PDF file.

Understanding CVE-2018-18459

Xpdf 4.00 vulnerability leading to a denial of service attack.

What is CVE-2018-18459?

The vulnerability in Xpdf 4.00 allows remote attackers to trigger a denial of service (NULL pointer dereference) by manipulating a PDF file.

The Impact of CVE-2018-18459

Exploiting this vulnerability can result in a denial of service, disrupting the availability of the Xpdf application.

Technical Details of CVE-2018-18459

Details of the vulnerability in Xpdf 4.00.

Vulnerability Description

The vulnerability lies in the DCTStream::getBlock function in the Stream.cc file, enabling attackers to exploit a NULL pointer dereference.

Affected Systems and Versions

Product: Xpdf 4.00
Versions: All versions of Xpdf 4.00 are affected.

Exploitation Mechanism

Attackers can exploit this vulnerability by using a specially crafted PDF file, such as through the pdftoppm tool.

Mitigation and Prevention

Protecting systems from CVE-2018-18459.

Immediate Steps to Take

Avoid opening PDF files from untrusted or unknown sources.
Implement file type and content filtering to detect malicious PDF files.
Consider using alternative PDF readers until a patch is available.

Long-Term Security Practices

Keep software and applications updated to mitigate known vulnerabilities.
Regularly monitor security advisories for Xpdf and apply patches promptly.

Patching and Updates

Check for updates or patches released by Xpdf to address the vulnerability.