CVE-2020-24370: ldebug.c in Lua 5.4.0 allows a negation overflow and segmentation fault in getlocal and setlocal as demonstrated by getlocal(32^31).
CVE-2020-24370 is a vulnerability in ldebug.c in Lua 5.4.0 allows a negation overflow and segmentation fault in getlocal and setlocal as demonstrated by getlocal(32^31)., rated Moderate by Microsoft, with a CVSS 3.1 base score of 5.3 (Medium). An attacker can exploit it remotely over the network, without any privileges and without user interaction. Microsoft has not reported exploitation in the wild. The EPSS model estimates a 3.83% probability of exploitation activity in the next 30 days, higher than 90% of all scored vulnerabilities. Microsoft released the fix on 30 June 2024 in the August 2020 Patch Tuesday. It affects 1 product in 1 product family (Other).
Key facts
- CVE ID
- CVE-2020-24370
- Severity
- Medium CVSS 5.3
- Microsoft severity
- Moderate
- Exploited in the wild
- No
- Publicly disclosed
- No
- Weakness
- CWE-191
- EPSS
- 3.83% (percentile 90%)
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- August 2020 Patch Tuesday
- Product families
- Other
CVSS score and vector
Microsoft scores CVE-2020-24370 at 5.3 (temporal 5.3) using CVSS 3.1. Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality impact | None |
| Integrity impact | None |
| Availability impact | Low |
Frequently asked questions (Microsoft)
Is Azure Linux the only Microsoft product that includes this open-source library and is therefore potentially affected by this vulnerability?
One of the main benefits to our customers who choose to use the Azure Linux distro is the commitment to keep it up to date with the most recent and most secure versions of the open source libraries with which the distro is composed. Microsoft is committed to transparency in this work which is why we began publishing CSAF/VEX in October 2025. See this blog post for more information. If impact to additional products is identified, we will update the CVE to reflect this.
Affected products (1)
Other
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| 19211-17084 | CBL-Mariner Releases | Security Update | 5.4.6-1 | No |
Exploitation and detection
Detection and weaponization
Weaponization maturity: Exploit.
Proof-of-concept repositories (2)
NIST NVD data
- NVD status
- Analyzed
- NVD CVSS
- 5.3 (MEDIUM)
- NVD weakness
- CWE-191
- Published to NVD
- NVD last modified
Affected configurations (CPE)
| Product | Vulnerable versions |
|---|---|
| lua 5.2.0 | all listed versions |
| lua 5.2.0 | all listed versions |
| lua 5.2.0 | all listed versions |
| lua 5.2.1 | all listed versions |
| lua 5.2.2 | all listed versions |
| lua 5.2.3 | all listed versions |
| lua 5.3.0 | all listed versions |
| lua 5.3.0 | all listed versions |
| lua 5.3.0 | all listed versions |
| lua 5.3.1 | all listed versions |
| lua 5.3.2 | all listed versions |
| lua 5.3.3 | all listed versions |
| lua 5.3.4 | all listed versions |
| lua 5.3.5 | all listed versions |
| lua 5.4.0 | all listed versions |
| lua 5.4.0 | all listed versions |
| lua 5.4.0 | all listed versions |
| fedora 31 | all listed versions |
| fedora 32 | all listed versions |
| debian linux 9.0 | all listed versions |
References
- http://lua-users.org/lists/lua-l/2020-07/msg00324.html (Exploit, Mailing List, Vendor Advisory)
- https://github.com/lua/lua/commit/a585eae6e7ada1ca9271607a4f48dfb17868ab7b (Patch, Third Party Advisory)
- https://lists.debian.org/debian-lts-announce/2020/09/msg00019.html (Mailing List, Third Party Advisory)
- https://lists.debian.org/debian-lts-announce/2023/06/msg00031.html (Third Party Advisory)
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/E6KONNG6UEI3FMEOY67NDZC32NBGBI44/ (Third Party Advisory)
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QXYMCIUNGK26VHAYHGP5LPW56G2KWOHQ/ (Third Party Advisory)
- http://lua-users.org/lists/lua-l/2020-07/msg00324.html (Exploit, Mailing List, Vendor Advisory)
- https://github.com/lua/lua/commit/a585eae6e7ada1ca9271607a4f48dfb17868ab7b (Patch, Third Party Advisory)
- https://lists.debian.org/debian-lts-announce/2020/09/msg00019.html (Mailing List, Third Party Advisory)
- https://lists.debian.org/debian-lts-announce/2023/06/msg00031.html (Third Party Advisory)
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/E6KONNG6UEI3FMEOY67NDZC32NBGBI44/ (Third Party Advisory)
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QXYMCIUNGK26VHAYHGP5LPW56G2KWOHQ/ (Third Party Advisory)
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |