CVE-2021-3657

high-risk
Published 2022-02-18

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.

Do I need to act?

~
5.7% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10 Critical
NETWORK / LOW complexity

Affected Products (4)

Isync

Affected Vendors

Debian Redhat Fedoraproject Isync Project

References (8)

Issue Tracking https://bugzilla.redhat.com/show_bug.cgi?id=2028932
Mailing List https://lists.debian.org/debian-lts-announce/2022/07/msg00001.html
Third Party Advisory https://security.gentoo.org/glsa/202208-15
Mailing List https://www.openwall.com/lists/oss-security/2021/12/03/1
Issue Tracking https://bugzilla.redhat.com/show_bug.cgi?id=2028932
Mailing List https://lists.debian.org/debian-lts-announce/2022/07/msg00001.html
Third Party Advisory https://security.gentoo.org/glsa/202208-15
Mailing List https://www.openwall.com/lists/oss-security/2021/12/03/1
51
/ 100
high-risk
Severity 32/34 · Critical
Exploitability 9/34 · Low
Exposure 10/34 · Low