CVE-2021-3657
9.8
CRITICAL · CVSS 3.1 · EPSS 3.5% (pctl 89)
In your normal cycle
Critical by CVSS (9.8), but no sign of active exploitation.
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.
Scoring
| CVSS | 9.8 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 3.49% — more likely to be exploited than 89% of all CVEs |
| Weakness | CWE-119 |
| On CISA KEV | no |
| Public exploit | none known |
| Published | 2022-02-18 |
| Last modified | 2026-06-17 |
Affected (4)
| Vendor | Product |
|---|---|
| debian | debian linux |
| fedoraproject | fedora |
| isync project | isync |
| redhat | enterprise linux |
References
- https://bugzilla.redhat.com/show_bug.cgi?id=2028932
- https://lists.debian.org/debian-lts-announce/2022/07/msg00001.html
- https://security.gentoo.org/glsa/202208-15
- https://www.openwall.com/lists/oss-security/2021/12/03/1
- https://bugzilla.redhat.com/show_bug.cgi?id=2028932
- https://lists.debian.org/debian-lts-announce/2022/07/msg00001.html
- https://security.gentoo.org/glsa/202208-15
- https://www.openwall.com/lists/oss-security/2021/12/03/1
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