CVE-2021-20247
7.4 · HIGHOverview
CVE-2021-20247 is a high-severity vulnerability affecting mbsync_project mbsync. It was published on February 23, 2021 and has a CVSS 3.1 base score of 7.4 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.4, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
A flaw was found in mbsync before v1.3.5 and v1.4.1. Validations of the mailbox names returned by IMAP LIST/LSUB do not occur allowing a malicious or compromised server to use specially crafted mailbox names containing '..' path components to access data outside the designated mailbox on the opposite end of the synchronization channel. The highest threat from this vulnerability is to data confidentiality and integrity.
Remediation
Check the references section for vendor advisories and patches from mbsync_project. Update mbsync to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| mbsync_project | mbsync | >= 0, < 1.3.5 | Affected |
References
Frequently Asked Questions
What is CVE-2021-20247?
CVE-2021-20247 is a high-severity vulnerability affecting mbsync_project mbsync. It was published on February 23, 2021 and has a CVSS 3.1 base score of 7.4 (HIGH).
How severe is CVE-2021-20247?
This vulnerability has a CVSS 3.1 base score of 7.4, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2021-20247?
Check the references section for vendor advisories and patches from mbsync_project. Update mbsync to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2021-20247?
CyberStrike's AI-powered security agents can automatically detect CVE-2021-20247 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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