CVE-2021-29241

CODESYS Gateway 3 before 3.5.16.70 has a NULL pointer dereference that may result in a denial of service (DoS).

Published: 2021-05-03 Last update: 2026-05-29 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-29241 is rated Moderate Risk (51/100): CVSS High severity, with medium exploitation likelihood (EPSS 0.41%). 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-2021-29241

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 2026-02-18 0.65% 0.41% -0.24%
2 2025-04-27 0.80% 0.65% -0.15%
3 2025-04-10 — 0.80% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-29241

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
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]
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 134c704f-9b21-4f2e-91b3-4a467353bcc0
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
 10.0 2.9 [email protected]

Weakness enumeration for CVE-2021-29241

Affected software / configurations for CVE-2021-29241

Vendor Product Version Raw CPE
codesys control_for_beaglebone_sl >= 3.0, < 4.0.1.0 cpe:2.3:a:codesys:control_for_beaglebone_sl:*:*:*:*:*:*:*:*
codesys control_for_empc-a\/imx6_sl >= 3.0, < 4.0.1.0 cpe:2.3:a:codesys:control_for_empc-a\/imx6_sl:*:*:*:*:*:*:*:*
codesys control_for_iot2000_sl >= 3.0, < 4.0.1.0 cpe:2.3:a:codesys:control_for_iot2000_sl:*:*:*:*:*:*:*:*
codesys control_for_linux_sl >= 3.0, < 4.0.1.0 cpe:2.3:a:codesys:control_for_linux_sl:*:*:*:*:*:*:*:*
codesys control_for_pfc100_sl >= 3.0, < 3.5.16.0 cpe:2.3:a:codesys:control_for_pfc100_sl:*:*:*:*:*:*:*:*
codesys control_for_pfc200_sl >= 3.0, < 3.5.16.0 cpe:2.3:a:codesys:control_for_pfc200_sl:*:*:*:*:*:*:*:*
codesys control_for_raspberry_pi_sl >= 3.0, < 4.0.1.0 cpe:2.3:a:codesys:control_for_raspberry_pi_sl:*:*:*:*:*:*:*:*
codesys control_runtime_system_toolkit >= 3.0, < 3.5.16.70 cpe:2.3:a:codesys:control_runtime_system_toolkit:*:*:*:*:*:*:*:*
codesys development_system >= 3.0, < 3.5.16.70 cpe:2.3:a:codesys:development_system:*:*:*:*:*:*:*:*
codesys edge_gateway >= 3.0, < 3.5.16.70 cpe:2.3:a:codesys:edge_gateway:*:*:*:*:*:windows:*:*
codesys edge_gateway >= 3.0, < 4.1.0.0 cpe:2.3:a:codesys:edge_gateway:*:*:*:*:*:linux:*:*
codesys gateway >= 3.0, < 3.5.16.70 cpe:2.3:a:codesys:gateway:*:*:*:*:*:*:*:*

References for CVE-2021-29241

cvelogic Threat Intelligence