CVE-2021-3657
9.8
CRITICAL
CVSS 3.1
EPSS 6.1%
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.
How to fix CVE-2021-3657
To remediate CVE-2021-3657, upgrade the affected package to a fixed version below.
- Debian/isync—upgrade to 1.3.0-2.2+deb11u1 or later
Is CVE-2021-3657 being exploited?
Moderate — EPSS is 6.1%. Track this CVE but it's not at the top of the prioritisation list.
Affected packages (1)
- from 0, < 1.3.0-2.2+deb11u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | CRITICAL9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |