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CVE Record

CVE-2019-19391: In LuaJIT through 2.0.5, as used in Moonjit before 2.1.2 and other products, debug.getinfo has a type confu...

In LuaJIT through 2.0.5, as used in Moonjit before 2.1.2 and other products, debug.getinfo has a type confusion issue that leads to arbitrary memory write or read operations, because certain cases involving valid stack levels and > options are mishandled. NOTE: The LuaJIT project owner states that the debug libary is unsafe by definition and that this is not a vulnerability. When LuaJIT was originally developed, the expectation was that the entire debug library had no security guarantees and thus it made no sense to assign CVEs. However, not all users of later LuaJIT derivatives share this perspective

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This issue concerns LuaJIT's debug library, which can mishandle certain debug.getinfo inputs and allow memory read or write behavior. Business urgency depends on whether applications expose LuaJIT or Moonjit debug capabilities to untrusted scripts. The LuaJIT maintainer disputes treating the debug library as a security boundary.

Executive priority

Prioritize review where Lua scripting is customer-accessible, plugin-based, or used for tenant customization. For internal trusted scripting only, track vendor guidance but avoid emergency action unless a distribution advisory applies.

Technical view

CVE-2019-19391 describes type confusion in debug.getinfo in LuaJIT through 2.0.5 and Moonjit before 2.1.2. The reported impact is arbitrary memory read or write when valid stack levels and certain options are mishandled. The CVE has no CVSS, CWE, or precise affected CPE data in the supplied record.

Likely exposure

Most exposure is likely in products embedding LuaJIT or Moonjit and allowing untrusted or semi-trusted Lua code to call the debug library. Systems using only trusted Lua code have materially lower risk, based on the maintainer's stated debug-library assumptions.

Exploitation context

The supplied sources do not show active exploitation, and the CVE is not listed as KEV. The issue is disputed by the LuaJIT project owner because the debug library was not designed to provide security guarantees.

Researcher notes

The central ambiguity is threat model: LuaJIT upstream does not view debug-library misuse as a vulnerability, while downstream users may rely on stronger isolation. Validate actual debug-library reachability before assigning operational severity.

Mitigation direction

  • Inventory LuaJIT through 2.0.5 and Moonjit before 2.1.2 usage.
  • Upgrade Moonjit deployments to 2.1.2 or later where applicable.
  • Check vendor or distribution advisories for LuaJIT package updates.
  • Do not expose the debug library to untrusted Lua scripts.
  • Treat embedded Lua scripting as trusted unless sandboxing is explicitly documented.

Validation and detection

  • Identify applications embedding LuaJIT or Moonjit runtimes.
  • Confirm whether untrusted users can supply Lua scripts.
  • Review whether scripts can access debug.getinfo or the debug library.
  • Check package versions against LuaJIT 2.0.5 and Moonjit 2.1.2 boundaries.
  • Document vendor posture where LuaJIT debug features are intentionally unsafe.
Prepared
Confidence
medium
Sources
4

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
0Timeline events
0ADP providers
3Source links

CVSS and timeline data

No CVSS vectors or timeline events were available in the normalized CVE source material.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
n/an/an/aListed
Weakness

CWE details

No CWE listed

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