CVE-2021-43331

In GNU Mailman before 2.1.36, a crafted URL to the Cgi/options.py user options page can execute arbitrary JavaScript for XSS.

Published: 2021-11-12 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-43331 is rated Moderate Risk (48.7/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.28%). EPSS rose +1.13% over the last day, indicating growing attacker interest. Review affected assets and schedule remediation.

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-2021-43331

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 2026-06-15 0.15% 1.28% +1.13%
2 2025-11-21 0.68% 0.15% -0.52%
3 2025-11-18 — 0.68% —

Full EPSS history (19 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-43331

CVSS metrics for this CVE.

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]
4.3 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]

Weakness enumeration for CVE-2021-43331

OS Trackers for CVE-2021-43331

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2021-43331
suse high CVE-2021-43331 severity important: SUSE including 2 source package names (mailman-2.1.15-9.6.29.1, mailman-2.1.17-3.26.1), 17 product×package rows across 17 product lines (HPE Helion OpenStack 8, SUSE Linux Enterprise Server 11 SP3-TERADATA, … (17 product lines)): Fixed 17. https://www.suse.com/security/cve/CVE-2021-43331/
ubuntu medium CVE-2021-43331 medium priority: Ubuntu including 1 source packages (mailman), 14 status rows across 14 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, trusty, upstream, xenial): DNE 9, released 3, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2021-43331

Affected software / configurations for CVE-2021-43331

Vendor Product Version Raw CPE
gnu mailman < 2.1.36 cpe:2.3:a:gnu:mailman:*:*:*:*:*:*:*:*
debian debian_linux 9.0 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

References for CVE-2021-43331

cvelogic Threat Intelligence