CVE-2021-21434 [Low] | XSS in Survey

Survey administrator can craft a survey in such way that malicious code can be executed in the agent interface (i.e. another agent who wants to make changes in the survey). This issue affects: OTRS AG Survey 6.0.x version 6.0.20 and prior versions; 7.0.x version 7.0.19 and prior versions.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.35%	0.66%	+0.31%
2	2025-11-18	0.31%	0.35%	+0.04%
3	2025-03-30	—	0.31%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.35%

0.66%

+0.31%

2025-11-18

0.31%

0.35%

+0.04%

2025-03-30

—

0.31%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
3.5	3.1	LOW	`CVSS:3.1/AV:N/AC:L/PR:H/UI:R/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:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:H) They need powerful rights—admin, root, or similar—before this pays off. 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: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.	0.9	2.5	[email protected]
4.8	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:H/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:H) They need powerful rights—admin, root, or similar—before this pays off. 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.	1.7	2.7	[email protected]
3.5	2.0	LOW	`AV:N/AC:M/Au:S/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:S) A single authentication is required. Confidentiality impact (C:N) No confidentiality impact. Integrity impact (I:P) Partial integrity impact. Availability impact (A:N) No availability impact.	6.8	2.9	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

3.5

3.1

LOW

CVSS:3.1/AV:N/AC:L/PR:H/UI:R/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:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:H): They need powerful rights—admin, root, or similar—before this pays off.
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: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.

0.9

2.5

[email protected]

4.8

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/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:H): They need powerful rights—admin, root, or similar—before this pays off.
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.

1.7

2.7

[email protected]

3.5

2.0

LOW

AV:N/AC:M/Au:S/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:S): A single authentication is required.
Confidentiality impact (C:N): No confidentiality impact.
Integrity impact (I:P): Partial integrity impact.
Availability impact (A:N): No availability impact.

6.8

2.9

[email protected]

OS Trackers for CVE-2021-21434

vendor	priority	summary	link
`ubuntu`	medium	CVE-2021-21434 medium priority: Ubuntu including 1 source packages (otrs2), 16 status rows across 16 suites (bionic, focal, groovy, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 8, needs-triage 5, ignored 3.	https://ubuntu.com/security/CVE-2021-21434

Affected software / configurations for CVE-2021-21434

Vendor	Product	Version	Raw CPE
otrs	survey	>= 6.0.0, <= 6.0.20	cpe:2.3:a:otrs:survey::::::::
otrs	survey	>= 7.0.0, <= 7.0.19	cpe:2.3:a:otrs:survey::::::::

References for CVE-2021-21434

URL	Tags
https://otrs.com/release-notes/otrs-security-advisory-2021-01/	Vendor Advisory

URL

CVE-2021-21434 | XSS in Survey Module

Exploit prediction scoring system (EPSS) score for CVE-2021-21434

Common vulnerability scoring system (CVSS) metrics for CVE-2021-21434

Weakness enumeration for CVE-2021-21434

OS Trackers for CVE-2021-21434

Affected software / configurations for CVE-2021-21434

References for CVE-2021-21434