CVE-2018-20748 : Security Advisory and Response
Learn about CVE-2018-20748, involving heap out-of-bounds write vulnerabilities in LibVNC versions before 0.9.12. Find out the impact, affected systems, exploitation risks, and mitigation steps.
Heap out-of-bounds write vulnerabilities were discovered in LibVNC versions before 0.9.12, specifically in the file rfbproto.c of the libvncclient component. The patch for CVE-2018-20019, aimed at addressing these vulnerabilities, was found to be incomplete.
Understanding CVE-2018-20748
This CVE involves multiple heap out-of-bounds write vulnerabilities in LibVNC's libvncclient/rfbproto.c file.
What is CVE-2018-20748?
CVE-2018-20748 refers to heap out-of-bounds write vulnerabilities in LibVNC versions prior to 0.9.12, particularly in the libvncclient component.
The Impact of CVE-2018-20748
These vulnerabilities could potentially be exploited by attackers to execute arbitrary code or cause a denial of service (DoS) condition on affected systems.
Technical Details of CVE-2018-20748
LibVNC before version 0.9.12 contains multiple heap out-of-bounds write vulnerabilities in libvncclient/rfbproto.c. The fix for CVE-2018-20019 was incomplete.
Vulnerability Description
The vulnerabilities in CVE-2018-20748 allow for unauthorized write access to memory areas beyond the allocated buffer, leading to potential code execution or DoS attacks.
Affected Systems and Versions
- Affected Systems: LibVNC versions before 0.9.12
- Affected Component: libvncclient/rfbproto.c
- Unaffected Versions: 0.9.12 and above
Exploitation Mechanism
Attackers can exploit these vulnerabilities by crafting malicious input to trigger the out-of-bounds write conditions, potentially leading to the execution of arbitrary code.
Mitigation and Prevention
It is crucial to take immediate steps to mitigate the risks posed by CVE-2018-20748.
Immediate Steps to Take
- Update LibVNC to version 0.9.12 or later to eliminate the vulnerabilities.
- Monitor for any unusual activities on the network that could indicate exploitation attempts.
Long-Term Security Practices
- Regularly update software and apply security patches to prevent known vulnerabilities.
- Implement network segmentation and access controls to limit the impact of potential attacks.
Patching and Updates
- Stay informed about security advisories and updates from LibVNC and relevant vendors.
- Continuously monitor for new patches and apply them promptly to ensure system security.