CVE-2019-16791 Explained : Impact and Mitigation
Learn about CVE-2019-16791 affecting postfix-mta-sts-resolver versions prior to 0.5.1. Understand the impact, technical details, and mitigation steps for this vulnerability.
Postfix-mta-sts-resolver version 0.5.1 and earlier may provide users with inaccurate responses, potentially downgrading the effective STS policy.
Understanding CVE-2019-16791
The vulnerability in postfix-mta-sts-resolver could lead to a downgrade of the effective Strict Transport Security (STS) policy.
What is CVE-2019-16791?
In rare cases, postfix-mta-sts-resolver versions prior to 0.5.1 may provide users with incorrect responses from the daemon, potentially resulting in a downgrade of the effective STS policy.
The Impact of CVE-2019-16791
- CVSS Score: 6.9 (Medium Severity)
- Attack Complexity: High
- Attack Vector: Local
- Confidentiality Impact: High
- Integrity Impact: High
- Privileges Required: High
- User Interaction: Required
- Scope: Changed
- Availability Impact: None
- Vulnerability Type: CWE-757: Selection of Less-Secure Algorithm During Negotiation ('Algorithm Downgrade')
Technical Details of CVE-2019-16791
The technical details of the CVE-2019-16791 vulnerability.
Vulnerability Description
Users of postfix-mta-sts-resolver before version 0.5.1 may receive incorrect responses from the daemon, potentially leading to a downgrade of the STS policy.
Affected Systems and Versions
- Affected Product: postfix-mta-sts-resolver
- Vendor: Snawoot
- Affected Versions: < 0.5.1
Exploitation Mechanism
The vulnerability can be exploited by receiving inaccurate responses from the daemon, causing a potential downgrade of the STS policy.
Mitigation and Prevention
Steps to mitigate and prevent exploitation of CVE-2019-16791.
Immediate Steps to Take
- Update postfix-mta-sts-resolver to version 0.5.1 or later.
- Monitor for any unusual behavior indicating a downgrade of the STS policy.
Long-Term Security Practices
- Regularly update software to the latest versions to address known vulnerabilities.
- Implement network monitoring to detect and respond to suspicious activities.
Patching and Updates
- Apply patches provided by the vendor promptly to address the vulnerability and prevent exploitation.