CVE-2020-12100 : What You Need to Know
Learn about CVE-2020-12100, a Dovecot vulnerability allowing denial of service via deeply nested MIME parts. Find mitigation steps and update recommendations here.
In Dovecot before 2.3.11.3, uncontrolled recursion in submission, lmtp, and lda allows remote attackers to cause a denial of service (resource consumption) via a crafted e-mail message with deeply nested MIME parts.
Understanding CVE-2020-12100
What is CVE-2020-12100?
CVE-2020-12100 is a vulnerability in Dovecot that enables remote attackers to trigger a denial of service by exploiting uncontrolled recursion in specific components.
The Impact of CVE-2020-12100
This vulnerability can lead to resource exhaustion, potentially disrupting email services and causing downtime for affected systems.
Technical Details of CVE-2020-12100
Vulnerability Description
The issue arises from uncontrolled recursion in submission, lmtp, and lda components of Dovecot, allowing attackers to exploit deeply nested MIME parts in email messages.
Affected Systems and Versions
- Dovecot versions before 2.3.11.3 are vulnerable to this issue.
Exploitation Mechanism
Attackers can exploit this vulnerability by sending specially crafted email messages with deeply nested MIME parts, triggering the uncontrolled recursion and leading to resource consumption.
Mitigation and Prevention
Immediate Steps to Take
- Update Dovecot to version 2.3.11.3 or later to mitigate the vulnerability.
- Monitor system resources for any unusual consumption that could indicate an ongoing attack.
Long-Term Security Practices
- Regularly update and patch email servers and related software to address known vulnerabilities.
- Implement email filtering mechanisms to detect and block malicious content in emails.
Patching and Updates
- Stay informed about security advisories and updates from Dovecot and relevant vendors to apply patches promptly.