vulnerability

Ubuntu: (CVE-2021-3657): isync vulnerability

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Severity

CVSS

(AV:N/AC:L/Au:N/C:P/I:P/A:P)

Published

Feb 18, 2022

Added

Jun 26, 2025

Modified

Mar 27, 2026

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.

Solution

no-fix-ubuntu-package

References

CVE-2021-3657
https://attackerkb.com/topics/CVE-2021-3657
CWE-119
EUVD-EUVD-2021-26952
https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-26952
https://www.cve.org/CVERecord?id=CVE-2021-3657
https://www.openwall.com/lists/oss-security/2021/12/03/1

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