CRITICAL · 9.8

CVE-2021-3657

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 ...

Vulnerability Description

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.

CVSS Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH

Affected Products

VendorProductVersions
Isync ProjectIsync< 1.4.4
FedoraprojectFedora35
RedhatEnterprise Linux7.0
DebianDebian Linux9.0

Related Weaknesses (CWE)

References

FAQ

What is CVE-2021-3657?

CVE-2021-3657 is a vulnerability with a CVSS score of 9.8 (CRITICAL). 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 ...

How severe is CVE-2021-3657?

CVE-2021-3657 has been rated CRITICAL with a CVSS base score of 9.8/10. This is considered a critical vulnerability requiring immediate attention.

Is there a patch for CVE-2021-3657?

Check the references section above for vendor advisories and patch information. Affected products include: Isync Project Isync, Fedoraproject Fedora, Redhat Enterprise Linux, Debian Debian Linux.