CVE-2023-1617 [Critical] | Authentication Bypass in Vc4

Improper Authentication vulnerability in B&R Industrial Automation B&R VC4 (VNC-Server modules). This vulnerability may allow an unauthenticated network-based attacker to bypass the authentication mechanism of the VC4 visualization on affected devices. The impact of this vulnerability depends on the functionality provided in the visualization. This issue affects B&R VC4: from 3.* through 3.96.7, from 4.0* through 4.06.7, from 4.1* through 4.16.3, from 4.2* through 4.26.8, from 4.3* through 4.34.6, from 4.4* through 4.45.1, from 4.5* through 4.45.3, from 4.7* through 4.72.9.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.43%	0.72%	+0.29%
2	2026-04-21	0.32%	0.43%	+0.11%
3	2026-04-15	—	0.32%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.43%

0.72%

+0.29%

2026-04-21

0.32%

0.43%

+0.11%

2026-04-15

—

0.32%

—

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	[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

[email protected]

Affected software / configurations for CVE-2023-1617

Vendor	Product	Version	Raw CPE
br-automation	vc4	< 3.96.8	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.0.0, <= 4.06.4	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.10.0, <= 4.16.3	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.20.0, <= 4.26.8	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.30.0, < 4.34.7	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.40.0, <= 4.45.1	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.50.0, <= 4.53.0	cpe:2.3:a:br-automation:vc4::::::::
br-automation	vc4	>= 4.70.0, < 4.73.0	cpe:2.3:a:br-automation:vc4::::::::

References for CVE-2023-1617

URL	Tags
https://www.br-automation.com/downloads_br_productcatalogue/assets/1681046878970-en-original-1.0.pdf	Vendor Advisory

URL

CVE-2023-1617 | Improper Authentication Mechanism in B&R VC4 Visualization

Exploit prediction scoring system (EPSS) score for CVE-2023-1617

Common vulnerability scoring system (CVSS) metrics for CVE-2023-1617

Weakness enumeration for CVE-2023-1617

Affected software / configurations for CVE-2023-1617

References for CVE-2023-1617