CVE-2021-24837 | Passster < 3.5.5.8 - Contributor+ Stored Cross-Site Scripting

The Passster WordPress plugin before 3.5.5.8 does not escape the area parameter of its shortcode, which could allow users with a role as low as Contributor to perform Cross-Site Scripting attacks.

Published: 2023-01-23 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-24837 is rated Low Risk (32.6/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.39%). 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-2021-24837

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 0.18% 0.39% +0.21%
2 2026-01-24 0.14% 0.18% +0.04%
3 2025-11-21 — 0.14% —

Full EPSS history (11 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-24837

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]

Weakness enumeration for CVE-2021-24837

Affected software / configurations for CVE-2021-24837

Vendor Product Version Raw CPE
passster_project passter < 3.5.5.8 cpe:2.3:a:passster_project:passter:*:*:*:*:*:wordpress:*:*

References for CVE-2021-24837

cvelogic Threat Intelligence