CVE catalog
CVE-2021-3657
isync: CVE-2021-3657
- Severity
- Critical · CVSS 9.8
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 3.49% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | isync | sid | 1.5.1-2 | fixed |
| Debian | isync | forky | 1.5.1-2 | fixed |
| Debian | isync | trixie | 1.5.1-1 | fixed |
| Debian | isync | bookworm | 1.4.4-5 | fixed |
| Opensuse | isync | tumbleweed | 1.4.4-1.1 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | isync | source | sid | 1.4.4-1 | not yet assigned | Not reported | Not reported |
| Debian | isync | source | forky | 1.4.4-1 | not yet assigned | Not reported | Not reported |
| Debian | isync | source | trixie | 1.4.4-1 | not yet assigned | Not reported | Not reported |
| Debian | isync | source | bookworm | 1.4.4-1 | not yet assigned | Not reported | Not reported |
| Opensuse | isync | rpm | tumbleweed | 1.4.4-1.1 | Not reported | OPENSUSE-SU-2024:11779-1 | Not reported |
OpenFactory catalog packages
[Debian 12 (Bookworm)]
- [isync]Fixed
Details (2)
1.4.4-5· amd64 · bookwormFixed · Fixed:
1.4.4-1dsa · isync · debian · bookworm; dsa · isync · debian · 12
1.4.4-5· arm64 · bookwormFixed · Fixed:
1.4.4-1dsa · isync · debian · bookworm; dsa · isync · debian · 12
[Debian 13 (Trixie)]
- [isync]Fixed
Details (2)
1.5.1-1· amd64 · trixieFixed · Fixed:
1.4.4-1dsa · isync · debian · 13
1.5.1-1· arm64 · trixieFixed · Fixed:
1.4.4-1dsa · isync · debian · 13
[openSUSE Tumbleweed]
Observed:
References
- [https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2024_11779-1.json]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2021-3657]
- [https://osv.dev/vulnerability/openSUSE-SU-2024:11779-1]
- [https://security-tracker.debian.org/tracker/CVE-2021-3657]
- [https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-3657.json]
[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]