CVE-2023-37556 | CODESYS Improper Input Validation in CmpAppBP

In multiple versions of multiple Codesys products, after successful authentication as a user, specific crafted network communication requests with inconsistent content can cause the CmpAppBP component to read internally from an invalid address, potentially leading to a denial-of-service condition. This vulnerability is different to CVE-2023-37552, CVE-2023-37553, CVE-2023-37554 and CVE-2023-37555.

Published: 2023-08-03 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2023-37556 is rated Moderate Risk (40.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.20%). Mandatory action: Review affected assets and schedule remediation.

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-2023-37556

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 2026-05-31 0.26% 0.20% -0.06%
2 2026-05-30 0.24% 0.26% +0.02%
3 2026-05-16 0.24%

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-37556

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
2.8 3.6 [email protected]

Weakness enumeration for CVE-2023-37556

Affected software / configurations for CVE-2023-37556

Vendor Product Version Raw CPE
codesys control_for_beaglebone_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_beaglebone_sl:*:*:*:*:*:*:*:*
codesys control_for_empc-a\/imx6_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_empc-a\/imx6_sl:*:*:*:*:*:*:*:*
codesys control_for_iot2000_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_iot2000_sl:*:*:*:*:*:*:*:*
codesys control_for_linux_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_linux_sl:*:*:*:*:*:*:*:*
codesys control_for_pfc100_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_pfc100_sl:*:*:*:*:*:*:*:*
codesys control_for_pfc200_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_pfc200_sl:*:*:*:*:*:*:*:*
codesys control_for_plcnext_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_plcnext_sl:*:*:*:*:*:*:*:*
codesys control_for_raspberry_pi_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_raspberry_pi_sl:*:*:*:*:*:*:*:*
codesys control_for_wago_touch_panels_600_sl < 4.10.0.0 cpe:2.3:a:codesys:control_for_wago_touch_panels_600_sl:*:*:*:*:*:*:*:*
codesys control_rte_sl < 3.5.19.20 cpe:2.3:a:codesys:control_rte_sl:*:*:*:*:*:*:*:*
codesys control_rte_sl_\(for_beckhoff_cx\) < 3.5.19.20 cpe:2.3:a:codesys:control_rte_sl_\(for_beckhoff_cx\):*:*:*:*:*:*:*:*
codesys control_runtime_system_toolkit < 3.5.19.20 cpe:2.3:a:codesys:control_runtime_system_toolkit:*:*:*:*:*:*:*:*
codesys control_win_sl < 3.5.19.20 cpe:2.3:a:codesys:control_win_sl:*:*:*:*:*:*:*:*
codesys development_system < 3.5.19.20 cpe:2.3:a:codesys:development_system:*:*:*:*:*:*:*:*
codesys hmi < 3.5.19.20 cpe:2.3:a:codesys:hmi:*:*:*:*:*:*:*:*
codesys safety_sil2 < 3.5.19.20 cpe:2.3:a:codesys:safety_sil2:*:*:*:*:*:*:*:*

References for CVE-2023-37556

URL Tags
https://cert.vde.com/en/advisories/VDE-2023-019/ Third Party Advisory
cvelogic Threat Intelligence