CVE-2021-41581 Explained : Impact and Mitigation
Learn about CVE-2021-41581, a vulnerability in LibreSSL allowing stack-based buffer over-read. Understand the impact, affected systems, exploitation, and mitigation steps.
CVE-2021-41581 relates to a stack-based buffer over-read vulnerability in LibreSSL through version 3.4.0, specifically in the x509_constraints_parse_mailbox function.
Understanding CVE-2021-41581
This CVE involves a buffer over-read issue in the mentioned function, potentially leading to security risks.
What is CVE-2021-41581?
The x509_constraints_parse_mailbox function in LibreSSL up to version 3.4.0 encounters a stack-based buffer over-read. An input exceeding DOMAIN_PART_MAX_LEN can cause the buffer to lack '\0' termination, resulting in possible exploitation.
The Impact of CVE-2021-41581
This vulnerability could allow attackers to exploit the buffer over-read, potentially leading to information disclosure, denial of service, or even remote code execution in certain scenarios.
Technical Details of CVE-2021-41581
This section delves into the technical aspects of the CVE.
Vulnerability Description
The issue arises in the x509_constraints_parse_mailbox function due to inadequate buffer termination when input exceeds a certain length, causing a stack-based buffer over-read.
Affected Systems and Versions
- Systems running LibreSSL up to version 3.4.0 are vulnerable to this issue.
Exploitation Mechanism
Attackers can exploit this vulnerability by providing specially crafted input that exceeds the maximum length, triggering the buffer over-read.
Mitigation and Prevention
It is crucial to take immediate actions to mitigate the risks posed by CVE-2021-41581.
Immediate Steps to Take
- Update LibreSSL to version 3.4.1 or later to fix the buffer over-read vulnerability.
- Implement input validation mechanisms to limit the length of user inputs.
Long-Term Security Practices
- Regularly monitor security advisories for LibreSSL and apply updates promptly.
- Conduct security audits to identify and address similar vulnerabilities in the codebase.
Patching and Updates
- Stay informed about security patches released by LibreSSL and apply them as soon as they are available to ensure the security of your systems.