Buffer overflow in Isync_project Isync

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 senders, could cause several different…

Vulnerability class: Buffer Overflow

EPSS: 0.035 (87.7th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-3657?
CVE-2021-3657 is a critical-severity vulnerability in Isync_project Isync, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.8/10. Published 2022-02-18.
How severe is CVE-2021-3657?
Critical severity. CVSS v3 base score is 9.8 out of 10.