CVE-2020-14309 : Exploit Details and Defense Strategies
Learn about CVE-2020-14309, a critical vulnerability in Grub2 versions before 2.06 that could allow attackers to execute a heap-based buffer overflow attack. Find out how to mitigate and prevent this security risk.
A vulnerability in Grub2 versions before 2.06 could allow an attacker to execute a heap-based buffer overflow attack.
Understanding CVE-2020-14309
What is CVE-2020-14309?
The vulnerability in Grub2 arises when handling squashfs filesystems with a symbolic link of a specific size, leading to a heap-based buffer overflow.
The Impact of CVE-2020-14309
The vulnerability allows an attacker to trigger a heap-based buffer overflow, potentially leading to arbitrary code execution or denial of service.
Technical Details of CVE-2020-14309
Vulnerability Description
An arithmetic overflow occurs due to a symbolic link with a name length of UINT32 bytes, resulting in a zero-size allocation and subsequent heap-based buffer overflow.
Affected Systems and Versions
- All Grub2 versions before 2.06
Exploitation Mechanism
The vulnerability can be exploited by crafting a malicious squashfs filesystem containing a symbolic link with a specific name length.
Mitigation and Prevention
Immediate Steps to Take
- Apply the vendor-supplied patches promptly to mitigate the vulnerability.
- Monitor vendor advisories for updates and follow best security practices.
Long-Term Security Practices
- Regularly update software and firmware to the latest versions.
- Implement network segmentation and least privilege access controls.
Patching and Updates
- Update Grub2 to version 2.06 or later to address the vulnerability.