# CVE-2019-6706: Lua 5.3.5 has a use-after-free in lua_upvaluejoin in lapi.c. For example a crash outcome might be achieved by an attacker who is able to trigger a debug.upvaluejoin call in which the arguments have certain relationships.

CVE-2019-6706 is fixed in 5 products on 1 platform, first by liblua5.3-0 5.3.3-1ubuntu0.18.04.1, released January 22, 2019. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2019-6706
- Priority: High
- CVSS: 7.5 (Important)
- EPSS: 0.1738
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jan 22, 2019
- Weakness: Use After Free
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2019-6706

## Description

The lua packages provide support for Lua, a powerful light-weight programming language designed for extending applications. Lua is also frequently used as a general-purpose, stand-alone language.  Security Fix(es):  * lua: use-after-free in lua_upvaluejoin in lapi.c resulting in denial of service (CVE-2019-6706)  For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.  Additional Changes:  For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.1 Release Notes linked from the References section.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | liblua5.3-0 Ubuntu 18.04.6 LTS (bionic) | 5.3.3-1ubuntu0.18.04.1 | [liblua5.3-0 5.3.3-1ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-liblua5.3-0-5.3.3-1ubuntu0.18.04.1.md) | Jan 22, 2019 |
| Linux | lua RHEL 8 | 0:5.3.4-11.el8 | [RHSA-2019:3706](https://patchblox.com/security/data/fix/linux/rhsa-2019-3706.md) | Nov 5, 2019 |
| Linux | lua ol 8 | 0:5.3.4-11.el8 | [ELSA-2019-3706](https://patchblox.com/security/data/fix/linux/elsa-2019-3706.md) | Nov 14, 2019 |
| Linux | lua-devel RHEL 8 | 0:5.3.4-11.el8 | [RHSA-2019:3706](https://patchblox.com/security/data/fix/linux/rhsa-2019-3706.md) | Nov 5, 2019 |
| Linux | lua-devel ol 8 | 0:5.3.4-11.el8 | [ELSA-2019-3706](https://patchblox.com/security/data/fix/linux/elsa-2019-3706.md) | Nov 14, 2019 |
| Linux | lua-libs RHEL 8 | 0:5.3.4-11.el8 | [RHSA-2019:3706](https://patchblox.com/security/data/fix/linux/rhsa-2019-3706.md) | Nov 5, 2019 |
| Linux | lua-libs ol 8 | 0:5.3.4-11.el8 | [ELSA-2019-3706](https://patchblox.com/security/data/fix/linux/elsa-2019-3706.md) | Nov 14, 2019 |
| Linux | lua5.3 Ubuntu 18.04.6 LTS (bionic) | 5.3.3-1ubuntu0.18.04.1 | [lua5.3 5.3.3-1ubuntu0.18.04.1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-lua5.3-5.3.3-1ubuntu0.18.04.1.md) | Jan 22, 2019 |

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