CVE-2021-3578

medium
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
5.5

Description

A flaw was found in mbsync before v1.3.6 and v1.4.2, where an unchecked pointer cast allows a malicious or compromised server to write an arbitrary integer value past the end of a heap-allocated structure by issuing an unexpected APPENDUID response. This could be plausibly exploited for remote code execution on the client.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2021-3578

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202106-27

OS impact

OSVersionStatusFixed in
arch archfixed1.4.2-1
debian debianbookwormfixed1.3.0-2.2
debian debianbullseyefixed1.3.0-2.2
debian debianforkyfixed1.3.0-2.2
debian debiansidfixed1.3.0-2.2
debian debiantrixiefixed1.3.0-2.2

References

Verify integrity in audit chain (admin only). AS-IS.