# CVE-2021-3578: isync: A flaw was found in mbsync before v1.3.6 and v1.4.2, where an unchecked pointer cast allows a malicious or compromise...

CVE-2021-3578 is fixed in isync on 1 platform, first by DEBIAN-CVE-2021-3578, released February 16, 2022. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-3578
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0104
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 16, 2022

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | isync Debian 12.15 (bookworm) | 1.3.0-2.2 | [DEBIAN-CVE-2021-3578](https://patchblox.com/security/data/fix/linux/debian-cve-2021-3578.md) | Feb 16, 2022 |
| Linux | isync Debian 13.5 (trixie) | 1.3.0-2.2 | [DEBIAN-CVE-2021-3578](https://patchblox.com/security/data/fix/linux/debian-cve-2021-3578.md) | Feb 16, 2022 |
| Linux | isync Debian 14 | 1.3.0-2.2 | [DEBIAN-CVE-2021-3578](https://patchblox.com/security/data/fix/linux/debian-cve-2021-3578.md) | Feb 16, 2022 |

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