CVE-2021-3741 | Stored Cross-site Scripting (XSS) in chatwoot/chatwoot

A stored cross-site scripting (XSS) vulnerability was discovered in chatwoot/chatwoot, affecting all versions prior to 2.6. The vulnerability occurs when a user uploads an SVG file containing a malicious XSS payload in the profile settings. When the avatar is opened in a new page, the custom JavaScript code is executed, leading to potential security risks.

Published: 2024-11-15 Last update: 2024-11-19 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-3741 is rated Low Risk (34.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.16%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3741

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-12-24 0.13% 0.16% +0.03%
2 2025-11-21 0.30% 0.13% -0.17%
3 2025-11-18 0.30%

Full EPSS history (7 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3741

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/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:L)
A normal user session is enough; they don’t have to be admin.
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.
2.3 2.7 [email protected]
7.8 3.0 HIGH
CVSS:3.0/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:L/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
1.2 6.0 [email protected]

Weakness enumeration for CVE-2021-3741

Affected software / configurations for CVE-2021-3741

Vendor Product Version Raw CPE
chatwoot chatwoot < 2.6.0 cpe:2.3:a:chatwoot:chatwoot:*:*:*:*:*:*:*:*

References for CVE-2021-3741

cvelogic Threat Intelligence