CVE-2021-29157 : Vulnerability Insights and Analysis
Discover the impact of CVE-2021-29157, a path traversal vulnerability in Dovecot before 2.3.15, allowing attackers to manipulate authentication and exploit HS256 keys.
Dovecot before 2.3.15 allows path traversal, enabling an attacker to manipulate OAuth2 authentication, leading to the use of a malicious HS256 validation key. This vulnerability arises during local JWT validation using the posix fs driver.
Understanding CVE-2021-29157
This section delves into the impact and technical details of the CVE.
What is CVE-2021-29157?
The vulnerability in Dovecot before version 2.3.15 allows attackers to exploit path traversal, tricking OAuth2 authentication into using an attacker-controlled HS256 validation key.
The Impact of CVE-2021-29157
The impact is rated as HIGH, with a CVSSv3.1 base score of 7.5. Attack complexity is high, with local attack vector and confidentiality, integrity, and privileges-required aspects affected.
Technical Details of CVE-2021-29157
This section explores the vulnerability description, affected systems, and exploitation mechanism.
Vulnerability Description
Dovecot before 2.3.15 suffers from a path traversal flaw that allows attackers to manipulate OAuth2 authentication for unauthorized key usage.
Affected Systems and Versions
All versions prior to 2.3.15 of Dovecot are affected by this vulnerability.
Exploitation Mechanism
Attackers with local filesystem access can exploit this vulnerability to force OAuth2 authentication to use a malicious HS256 validation key.
Mitigation and Prevention
In this section, you will find guidelines on immediate steps to take to secure systems and prevent exploitation, as well as long-term security measures.
Immediate Steps to Take
Users are advised to update Dovecot to version 2.3.15 or later to mitigate the path traversal vulnerability.
Long-Term Security Practices
Implement regular security patches and updates, conduct security audits, and monitor for unusual activities to enhance overall system security.
Patching and Updates
Stay informed about security advisories and promptly apply patches released by Dovecot to address vulnerabilities and strengthen system defenses.