CVE-2021-3657: Buffer Overflow

Published Dec 3, 2021
·
Updated

A flaw was found in mbsync versions prior to 1.4.4. Due to inadequate handling of extremely large (>=2GiB) IMAP literals, malicious or compromised IMAP servers, and hypothetically even external email senders, could cause several different buffer overflows, which could conceivably be exploited for remote code execution.

Affected Software

6 affected componentsFixes available
redhat/isync<1.4.4
1.4.4
debian/isync
1.3.0-2.2+deb11u11.4.4-5
Isync Project Isync<1.4.4
Fedoraproject Fedora=35
redhat Enterprise Linux=7.0
Debian Debian Linux=9.0

Event History

Dec 3, 2021
Data Sourced
via Red Hat·06:39 PM
DescriptionSeverityAffected Software
Feb 18, 2022
CVE Published
via MITRE·05:50 PM
Data Sourced
via MITRE·05:50 PM
DescriptionWeakness

Frequently Asked Questions

1

What is the severity of CVE-2021-3657?

CVE-2021-3657 has a high severity due to the potential for buffer overflows that could lead to code execution.

2

How do I fix CVE-2021-3657?

To fix CVE-2021-3657, upgrade mbsync to version 1.4.4 or higher.

3

What versions of isync are affected by CVE-2021-3657?

Versions of isync prior to 1.4.4 are affected by CVE-2021-3657.

4

Can CVE-2021-3657 be exploited remotely?

Yes, CVE-2021-3657 can potentially be exploited by malicious IMAP servers or external email senders.

5

What platforms are impacted by CVE-2021-3657?

CVE-2021-3657 impacts systems running affected versions of isync on various platforms including Red Hat, Debian, and Fedora.

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203