CVE-2021-38944 [Medium] | XSS in Datapower Gateway

IBM DataPower Gateway 10.0.2.0 through 1.0.3.0, 10.0.1.0 through 10.0.1.5, and 2018.4.1.0 through 2018.4.1.18 is vulnerable to HTTP header injection, caused by improper validation of input by the HOST headers. This could allow an attacker to conduct various attacks against the vulnerable system, including cross-site scripting, cache poisoning or session hijacking. IBM X-Force ID: 211236.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.21%	0.54%	+0.32%
2	2025-05-27	0.30%	0.21%	-0.09%
3	2025-05-25	—	0.30%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.21%

0.54%

+0.32%

2025-05-27

0.30%

0.21%

-0.09%

2025-05-25

—

0.30%

—

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]
4.8	3.0	MEDIUM	`CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/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: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: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: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.	2.2	2.5	[email protected]
4.3	2.0	MEDIUM	`AV:N/AC:M/Au:N/C:N/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:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	8.6	2.9	[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]

4.8

3.0

MEDIUM

CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/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: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: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: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.

2.2

2.5

[email protected]

4.3

2.0

MEDIUM

AV:N/AC:M/Au:N/C:N/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:N): No confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

8.6

2.9

[email protected]

Affected software / configurations for CVE-2021-38944

Vendor	Product	Version	Raw CPE
ibm	datapower_gateway	>= 10.0.1.0, <= 10.0.1.5	cpe:2.3:a:ibm:datapower_gateway::::::::
ibm	datapower_gateway	>= 10.0.2.0, <= 10.0.3.0	cpe:2.3:a:ibm:datapower_gateway::::::::
ibm	datapower_gateway	>= 2018.4.1.0, <= 2018.4.1.18	cpe:2.3:a:ibm:datapower_gateway::::::::

References for CVE-2021-38944

URL	Tags
https://exchange.xforce.ibmcloud.com/vulnerabilities/211236	VDB Entry Vendor Advisory
https://www.ibm.com/support/pages/node/6587070	Patch Vendor Advisory

URL

CVE-2021-38944

Exploit prediction scoring system (EPSS) score for CVE-2021-38944

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38944

Weakness enumeration for CVE-2021-38944

Affected software / configurations for CVE-2021-38944

References for CVE-2021-38944