# CVE-2019-20840: libvncclient1: An issue was discovered in LibVNCServer before 0.9.13

CVE-2019-20840 is fixed in 3 products on 1 platform, first by libvncclient1 0.9.11+dfsg-1ubuntu1.3, released June 17, 2020. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2019-20840
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0273
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 17, 2020

## Description

An issue was discovered in LibVNCServer before 0.9.13. libvncserver/ws_decode.c can lead to a crash because of unaligned accesses in hybiReadAndDecode.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libvncclient1 Ubuntu 18.04.6 LTS (bionic) | 0.9.11+dfsg-1ubuntu1.3 | [libvncclient1 0.9.11+dfsg-1ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libvncclient1-0.9.11-dfsg-1ubuntu1.3.md) | Jun 17, 2020 |
| Linux | libvncserver-config Ubuntu 18.04.6 LTS (bionic) | 0.9.11+dfsg-1ubuntu1.3 | [libvncserver-config 0.9.11+dfsg-1ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libvncserver-config-0.9.11-dfsg-1ubuntu1.3.md) | Jun 17, 2020 |
| Linux | libvncserver1 Ubuntu 18.04.6 LTS (bionic) | 0.9.11+dfsg-1ubuntu1.3 | [libvncserver1 0.9.11+dfsg-1ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libvncserver1-0.9.11-dfsg-1ubuntu1.3.md) | Jun 17, 2020 |

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