Skip to content
Fencer Vulns
medium 5.5

CVE-2021-44647 json

Lua v5.4.3 and above are affected by SEGV by type confusion in funcnamefromcode function in ldebug.c which can cause a local denial of serv…

published 2022-01-11 4 y ago modified 2026-09-08 2 mo ago also BIT-lua-2021-44647 , EUVD-2021-31468 , JLSEC-2026-557

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 39%
public exploits
0
none known

Summary

Lua v5.4.3 and above are affected by SEGV by type confusion in funcnamefromcode function in ldebug.c which can cause a local denial of service.

Patch / fix

  • bitnami lua 5.4.4
  • julia Lua_jll 5.4.4+0
  • lua5.4 Debian 14, Debian 13, Debian 12 5.4.4-1

debian advisories DEBIAN-CVE-2021-44647

  • lua55 openSUSE Tumbleweed 5.5.0~beta1-1.1

opensuse advisories openSUSE-SU-2025:15401-1

  • memcached Azure Linux 3.0 1.6.27-3
  • ntopng Azure Linux 3.0 5.2.1-5
  • lua CBL-Mariner 2.0 5.4.3-3

azure linux advisories AZL-41327AZL-41797AZL-9317

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-44647 updated cvss 5.5

lua: type confusion in funcnamefromcode in ldebug.c could result in local DoS

  • Red Hat Enterprise Linux 6 lua Red Hat Enterprise Linux 7 lua Red Hat Enterprise Linux 8 lua, lua-libs Red Hat Enterprise Linux 9 lua, lua-libs Red Hat JBoss Core Services lua
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.45% chance of exploitation in the next 30 days, higher than 39% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • lua-users.org http://lua-users.org/lists/lua-l/2021-11/msg00195.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 2.1 AV:L/AC:L/Au:N/C:N/I:N/A:P
OSV 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami lua
>=5.4.3, <5.4.4
5.4.4
julia Lua_jll
>=5.4.3+0, <5.4.4+0
5.4.4+0

Classification

Weakness
  • CWE-843 Access of Resource Using Incompatible Type

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.