CVE-2021-33485 [Critical] | Memory Corruption in Control

CVE-2021-33485 is rated Moderate Risk (60/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.39%). Review affected assets and schedule remediation.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-02-18	0.54%	0.39%	-0.15%
2	2025-08-18	0.67%	0.54%	-0.13%
3	2025-03-30	—	0.67%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-02-18

0.54%

0.39%

-0.15%

2025-08-18

0.67%

0.54%

-0.13%

2025-03-30

—

0.67%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	[email protected]
9.8	3.1	CRITICAL	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	3.9	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0
7.5	2.0	HIGH	`AV:N/AC:L/Au:N/C:P/I:P/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:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:P) Partial availability impact.	10.0	6.4	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

[email protected]

9.8

3.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

3.9

5.9

134c704f-9b21-4f2e-91b3-4a467353bcc0

7.5

2.0

HIGH

AV:N/AC:L/Au:N/C:P/I:P/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:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:P): Partial availability impact.

10.0

6.4

[email protected]

Affected software / configurations for CVE-2021-33485

Vendor	Product	Version	Raw CPE
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::beaglebone_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::empc-a\/imx6_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::iot2000_sl::*
codesys	control	<= 4.2.0.0	cpe:2.3:a:codesys:control::::::linux_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::pfc100_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::pfc200_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::plcnext_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::raspberry_pi_sl::*
codesys	control	< 4.2.0.0	cpe:2.3:a:codesys:control::::::wago_touch_panels_600_sl::*
codesys	control_rte	< 3.5.17.10	cpe:2.3:a:codesys:control_rte::::::-::*
codesys	control_rte	< 3.5.17.10	cpe:2.3:a:codesys:control_rte::::::beckhoff_cx::*
codesys	control_runtime_system_toolkit	< 3.5.17.10	cpe:2.3:a:codesys:control_runtime_system_toolkit::::::::
codesys	control_win_sl	< 3.5.17.10	cpe:2.3:a:codesys:control_win_sl::::::::
codesys	embedded_target_visu_toolkit	< 3.5.17.10	cpe:2.3:a:codesys:embedded_target_visu_toolkit::::::::
codesys	hmi	< 3.5.17.10	cpe:2.3:a:codesys:hmi::::::::
codesys	remote_target_visu_toolkit	< 3.5.17.10	cpe:2.3:a:codesys:remote_target_visu_toolkit::::::::

References for CVE-2021-33485

URL	Tags
https://customers.codesys.com/index.php?eID=dumpFile&t=f&f=14805&token=f0b86f99bb302ddd4aadec483aed5f5d3fddbf1a&download=	Vendor Advisory

URL

CVE-2021-33485

Exploit prediction scoring system (EPSS) score for CVE-2021-33485

Common vulnerability scoring system (CVSS) metrics for CVE-2021-33485

Weakness enumeration for CVE-2021-33485

GitHub Security Advisory for CVE-2021-33485

Affected software / configurations for CVE-2021-33485

References for CVE-2021-33485