CVE-2023-3040 | Out of Bounds Access Leading to Undefined Behavior

A debug function in the lua-resty-json package, up to commit id 3ef9492bd3a44d9e51301d6adc3cd1789c8f534a (merged in PR #14) contained an out of bounds access bug that could have allowed an attacker to launch a DoS if the function was used to parse untrusted input data. It is important to note that because this debug function was only used in tests and demos, it was not exploitable in a normal environment.

Published: 2023-06-14 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-3040 is rated Low Risk (32.4/100): CVSS Low severity, with low exploitation likelihood (EPSS 0.71%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2023-3040

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.10% 0.71% +0.61%
2 2026-03-04 0.05% 0.10% +0.06%
3 2026-03-01 — 0.05% —

Full EPSS history (39 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-3040

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
3.7 3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.2 1.4 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2023-3040

Affected software / configurations for CVE-2023-3040

Vendor Product Version Raw CPE
cloudflare lua-resty-json < 2023-05-05 cpe:2.3:a:cloudflare:lua-resty-json:*:*:*:*:*:*:*:*

References for CVE-2023-3040

cvelogic Threat Intelligence