CVE-2021-22283 [Medium] | Security Vulnerability in Smu615 Firmware

Improper Initialization vulnerability in ABB Relion protection relays - 611 series, ABB Relion protection relays - 615 series IEC 4.0 FP1, ABB Relion protection relays - 615 series CN 4.0 FP1, ABB Relion protection relays - 615 series IEC 5.0, ABB Relion protection relays - 615 series IEC 5.0 FP1, ABB Relion protection relays - 620 series IEC/CN 2.0, ABB Relion protection relays - 620 series IEC/CN 2.0 FP1, ABB Relion protection relays - REX640 PCL1, ABB Relion protection relays - REX640 PCL2, ABB Relion protection relays - REX640 PCL3, ABB Relion protection relays - RER615, ABB Remote Monitoring and Control - REC615, ABB Merging Unit- SMU615 allows Communication Channel Manipulation.This issue affects Relion protection relays - 611 series: from 1.0.0 before 2.0.3; Relion protection relays - 615 series IEC 4.0 FP1: from 4.1.0 before 4.1.9; Relion protection relays - 615 series CN 4.0 FP1: from 4.1.0 before 4.1.8; Relion protection relays - 615 series IEC 5.0: from 5.0.0 before 5.0.12; Relion protection relays - 615 series IEC 5.0 FP1: from 5.1.0 before 5.1.20; Relion protection relays - 620 series IEC/CN 2.0: from 2.0.0 before 2.0.11; Relion protection relays - 620 series IEC/CN 2.0 FP1: from 2.1.0 before 2.1.15; Relion protection relays - REX640 PCL1: from 1.0.0 before 1.0.8; Relion protection relays - REX640 PCL2: from 1.1.0 before 1.1.4; Relion protection relays - REX640 PCL3: from 1.2.0 before 1.2.1; Relion protection relays - RER615: from 2.0.0 before 2.0.3; Remote Monitoring and Control - REC615: from 1.0.0 before 2.0.3; Merging Unit- SMU615: from 1.0.0 before 1.0.2.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.05%	0.17%	+0.12%
2	2025-03-17	0.04%	0.05%	+0.01%
3	2023-03-07	—	0.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.05%

0.17%

+0.12%

2025-03-17

0.04%

0.05%

+0.01%

2023-03-07

—

0.04%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.2	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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.	2.5	3.6	[email protected]
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. 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.	1.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.2

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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.

2.5

3.6

[email protected]

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
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.

1.8

3.6

[email protected]

Affected software / configurations for CVE-2021-22283

Vendor	Product	Version	Raw CPE
abb	smu615_firmware	< 1.0.2	cpe:2.3:o:abb:smu615_firmware::::::::
abb	rec615_firmware	< 2.0.3	cpe:2.3:o:abb:rec615_firmware::::::::
abb	rer615_firmware	< 2.0.3	cpe:2.3:o:abb:rer615_firmware::::::::
abb	evd4_firmware	—	cpe:2.3:o:abb:evd4_firmware::::::::
abb	ref615r_firmware	—	cpe:2.3:o:abb:ref615r_firmware::::::::
abb	rex640_pcl3_firmware	< 1.2.1	cpe:2.3:o:abb:rex640_pcl3_firmware::::::::
abb	rex640_pcl2_firmware	< 1.1.4	cpe:2.3:o:abb:rex640_pcl2_firmware::::::::
abb	rex640_pcl1_firmware	< 1.0.8	cpe:2.3:o:abb:rex640_pcl1_firmware::::::::
abb	rer620_firmware	—	cpe:2.3:o:abb:rer620_firmware::::::::
abb	relion_611_firmware	< 2.0.3	cpe:2.3:o:abb:relion_611_firmware::::::::
abb	ref615_iec_firmware	—	cpe:2.3:o:abb:ref615_iec_firmware::::::::
abb	ref615_ansi_firmware	—	cpe:2.3:o:abb:ref615_ansi_firmware::::::::
abb	red615_iec_firmware	—	cpe:2.3:o:abb:red615_iec_firmware::::::::
abb	relion_615_iec_firmware	—	cpe:2.3:o:abb:relion_615_iec_firmware::::::::
abb	relion_615_cn_firmware	—	cpe:2.3:o:abb:relion_615_cn_firmware::::::::
abb	relion_615_ansi_firmware	—	cpe:2.3:o:abb:relion_615_ansi_firmware::::::::
abb	relion_615_iec_firmware	< 4.1.9	cpe:2.3:o:abb:relion_615_iec_firmware::::::::
abb	relion_615_cn_firmware	< 4.1.8	cpe:2.3:o:abb:relion_615_cn_firmware::::::::
abb	relion_615_iec_firmware	< 5.0.12	cpe:2.3:o:abb:relion_615_iec_firmware::::::::
abb	relion_615_iec_firmware	< 5.1.20	cpe:2.3:o:abb:relion_615_iec_firmware::::::::
abb	relion_620_iec_firmware	< 2.0.11	cpe:2.3:o:abb:relion_620_iec_firmware::::::::
abb	relion_620_cn_firmware	< 2.0.11	cpe:2.3:o:abb:relion_620_cn_firmware::::::::
abb	relion_620_ansi_firmware	—	cpe:2.3:o:abb:relion_620_ansi_firmware::::::::
abb	relion_620_iec_firmware	< 2.1.15	cpe:2.3:o:abb:relion_620_iec_firmware::::::::
abb	relion_620_cn_firmware	< 2.1.15	cpe:2.3:o:abb:relion_620_cn_firmware::::::::

References for CVE-2021-22283

URL	Tags
https://search.abb.com/library/Download.aspx?DocumentID=2NGA001147&LanguageCode=en&DocumentPartId=&Action=Launch	Vendor Advisory

URL

CVE-2021-22283 | MMS File Transfer Vulnerability impact on Distribution Automation products

Exploit prediction scoring system (EPSS) score for CVE-2021-22283

Common vulnerability scoring system (CVSS) metrics for CVE-2021-22283

Weakness enumeration for CVE-2021-22283

Affected software / configurations for CVE-2021-22283

References for CVE-2021-22283