Lua through 5.4.0 allows a stack redzone cross in luaO_pushvfstring because a protection mechanism wrongly calls luaD_callnoyield twice in…

published 2020-08-13 6 y ago modified 2026-09-08 2 mo ago also BIT-lua-2020-24342 , EUVD-2020-17076

cvss: 7.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.1%; EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits: 0; none known

Lua through 5.4.0 allows a stack redzone cross in luaO_pushvfstring because a protection mechanism wrongly calls luaD_callnoyield twice in a row.

Patch / fix

fixed in 1 distros 2 links 1

bitnami lua 5.4.1

debian opensuse

lua5.4 Debian 14, Debian 13, Debian 12 5.4.1-1

debian advisories DEBIAN-CVE-2020-24342

lua55 openSUSE Tumbleweed 5.5.0~beta1-1.1

opensuse advisories openSUSE-SU-2025:15401-1

github.com/lua/lua@34affe7 commit

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-2020-24342 updated 2026-11-05 cvss 7.8

lua: buffer overflow in luaO_pushvfstring

Red Hat Enterprise Linux 6 lua Red Hat Enterprise Linux 7 lua Red Hat Enterprise Linux 8 lua, lua-libs
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

1.08% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

lua-users.org http://lua-users.org/lists/lua-l/2020-07/msg00052.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD	2.0	6.8	AV:N/AC:M/Au:N/C:P/I:P/A:P
OSV	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected packages

ecosystem	package	affected	fixed in
bitnami	lua	>=5.4.0, <5.4.1	5.4.1

Classification

Weakness

CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

github.com /lua/lua/commit/34affe7a63fc5d842580a9f23616d057e17dfe27
patch, third-party-advisory, advisory
lua-users.org /lists/lua-l/2020-07/msg00052.html
exploit, mailing-list, vendor-advisory, advisory
lists.fedoraproject.org /archives/list/package-announce%40lists.fedoraproject.org/message/QA5Q5MDQMTGXRQO3PAQ4EZFTYWJXZM5N/
vendor-advisory, web
nvd.nist.gov /vuln/detail/CVE-2020-24342
web

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.

Summary