CVE-2020-4490 [Medium] | Security Bypass in Business Automation Workflow

IBM Business Automation Workflow 18 and 19, and IBM Business Process Manager 8.0, 8.5, and 8.6 could allow a remote attacker to bypass security restrictions, caused by a reverse tabnabbing flaw. An attacker could exploit this vulnerability and redirect a vitcim to a phishing site. IBM X-Force ID: 181989

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2023-03-07	1.05%	0.08%	-0.97%
2	2022-04-01	2.56%	1.05%	-1.51%
3	2022-02-04	—	2.56%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2023-03-07

1.05%

0.08%

-0.97%

2022-04-01

2.56%

1.05%

-1.51%

2022-02-04

—

2.56%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
6.1	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N` 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:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. Scope (S:C) Breaking this can reach past the original component and bite other resources—bigger blast radius. Confidentiality (C:L) Some sensitive info could get out, but not a total data dump. Integrity (I:L) Attackers could change some data, but it’s limited—not everything goes. Availability (A:N) Service keeps running; no real outage angle.	2.8	2.7	[email protected]
5.3	3.0	MEDIUM	`CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N` 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:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:N) No account or special rights needed—anonymous or random user is enough. User interaction (UI:R) A real person has to do something—click, install, enable—otherwise it doesn’t land. 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:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:N) Service keeps running; no real outage angle.	1.6	3.6	[email protected]
5.8	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:P/I:P/A:N` Click to expand Access vector (AV:N) Can be exploited remotely over network reachability. Access complexity (AC:M) Exploitation needs some favorable conditions, but not exceptional ones. Authentication (AU:N) No authentication is required. Confidentiality impact (C:P) Partial confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	8.6	4.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

6.1

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N 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:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C): Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L): Some sensitive info could get out, but not a total data dump.
Integrity (I:L): Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N): Service keeps running; no real outage angle.

2.8

2.7

[email protected]

5.3

3.0

MEDIUM

CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N 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:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N): No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R): A real person has to do something—click, install, enable—otherwise it doesn’t land.
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:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N): Service keeps running; no real outage angle.

1.6

3.6

[email protected]

5.8

2.0

MEDIUM

AV:N/AC:M/Au:N/C:P/I:P/A:N Click to expand

Access vector (AV:N): Can be exploited remotely over network reachability.
Access complexity (AC:M): Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N): No authentication is required.
Confidentiality impact (C:P): Partial confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

8.6

4.9

[email protected]

Affected software / configurations for CVE-2020-4490

Vendor	Product	Version	Raw CPE
ibm	business_automation_workflow	18.0.0.0	cpe:2.3:a:ibm:business_automation_workflow:18.0.0.0:::::::*
ibm	business_automation_workflow	19.0.0.0	cpe:2.3:a:ibm:business_automation_workflow:19.0.0.0:::::::*
ibm	business_process_manager	8.0.0.0	cpe:2.3:a:ibm:business_process_manager:8.0.0.0:::::::*
ibm	business_process_manager	8.5.0.0	cpe:2.3:a:ibm:business_process_manager:8.5.0.0:::::::*
ibm	business_process_manager	8.6.0.0	cpe:2.3:a:ibm:business_process_manager:8.6.0.0:::::::*

References for CVE-2020-4490

URL	Tags
https://exchange.xforce.ibmcloud.com/vulnerabilities/181989	VDB Entry Vendor Advisory
https://www.ibm.com/support/pages/node/6217550	Vendor Advisory

URL

CVE-2020-4490

Exploit prediction scoring system (EPSS) score for CVE-2020-4490

Common vulnerability scoring system (CVSS) metrics for CVE-2020-4490

Weakness enumeration for CVE-2020-4490

Affected software / configurations for CVE-2020-4490

References for CVE-2020-4490