# CVE-2017-3243: Oracle MySQL and MariaDB denial of service in Charsets component

Source: https://junglewise.ai/threats/cve-2017-3243-oracle-mysql-and-mariadb-denial-of-service-in-charsets-component  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2017-01-27. Updated: 2026-05-13  
License: CC BY 4.0 with a link back

CVE-2017-3243 · Severity: medium · CVSS 4.4 · Published 2017-01-27

A vulnerability in the MySQL and MariaDB database servers could allow a high-privileged user to cause a complete denial of service. By exploiting a flaw in the character set handling component, an attacker can cause the database to hang or crash repeatedly. This impacts the availability of applications and services that rely on these databases for data storage and retrieval.

Technologies: [Oracle MySQL Server](https://junglewise.ai/threats/technologies/mysql-server). Vendors: [Oracle](https://junglewise.ai/threats/vendors/oracle).

## Quick answers

**Is CVE-2017-3243 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2017-3243 being exploited in the wild.

**How severe is CVE-2017-3243?** Medium severity, with a CVSS score of 4.4, published 27 January 2017.

**Which products and versions are affected?** Oracle MySQL Server 5.5.53 and earlier.

**Is there a fix for CVE-2017-3243?** A patch was published on 2017-01-19: Debian released fixed mysql-5.5 packages Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2017-3243 attacked?** It is attacked over the network, in a hosted service.

**Am I affected by CVE-2017-3243?** Check whether you run Oracle MySQL Server at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A vulnerability exists in the 'Server: Charsets' subcomponent of Oracle MySQL and MariaDB. It is classified as a denial of service (DoS) vulnerability that is difficult to exploit. A high-privileged attacker with network access via multiple protocols can trigger a hang or a frequently repeatable crash of the MySQL Server. The issue affects MySQL versions 5.5.53 and earlier, as well as several MariaDB versions. Patches were released in MySQL 5.5.54 and MariaDB 10.0.29 and 10.1.21.

## Affected products

- Oracle MySQL Server 5.5.53 and earlier
- MariaDB Foundation MariaDB 5.5.0 to 5.5.53, 10.0.0 to 10.0.28, 10.1.0 to 10.1.20

## Timeline

- 2017-01-17: advisory: Oracle Critical Patch Update (CPU) released
- 2017-01-19: patched: Debian released fixed mysql-5.5 packages
- 2017-01-27: disclosed: NVD publication date

## References

- [http://www.debian.org/security/2017/dsa-3767](http://www.debian.org/security/2017/dsa-3767)
- [http://www.debian.org/security/2017/dsa-3770](http://www.debian.org/security/2017/dsa-3770)
- [http://www.oracle.com/technetwork/security-advisory/cpujan2017-2881727.html](http://www.oracle.com/technetwork/security-advisory/cpujan2017-2881727.html)
- [http://www.securityfocus.com/bid/95538](http://www.securityfocus.com/bid/95538)
- [http://www.securitytracker.com/id/1037640](http://www.securitytracker.com/id/1037640)
- [https://access.redhat.com/errata/RHSA-2017:2192](https://access.redhat.com/errata/RHSA-2017:2192)
- [https://access.redhat.com/errata/RHSA-2018:0279](https://access.redhat.com/errata/RHSA-2018:0279)

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