CVE-2021-38339

MEDIUM

The Simple Matted Thumbnails WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a reflected $_SERVER["PHP_SELF"] value in the ~/simple-matted-thumbnail.php file which allows at...

Affects 1 product across 1 vendor.

CVSS 3.16.1
EPSS0.9%
Percentile59th
PatchUnknown
CVSS Vector — Plain English Remotely exploitable over the network, low complexity, no authentication required, requires user interaction, can impact systems beyond the vulnerable component, no availability impact.
CWE Weakness Definitions
CWE-79: Cross-Site Scripting (XSS)

Attacker injects malicious scripts into web pages viewed by other users, executing in the victim's browser context.

Related Attack Patterns (CAPEC)
CAPEC-85 AJAX Footprinting
via CWE-79
CAPEC-209 XSS Using MIME Type Mismatch
via CWE-79
CAPEC-588 DOM-Based XSS
via CWE-79
CAPEC-591 Reflected XSS
via CWE-79
CAPEC-592 Stored XSS
via CWE-79
Show all 6
via CWE-79

Mapping is CWE-to-CAPEC per MITRE CAPEC 3.9.

◆ AI Analysis — automated analysis, not human-reviewed

The Simple Matted Thumbnails WordPress plugin is vulnerable to Reflected Cross-Site Scripting (XSS) due to improper handling of the $_SERVER['PHP_SELF'] variable in versions up to and including 1.01.

BSID: BS-2021-GLOBAL-304878-M • Model: /workspace/models/qwen2.5-coder-32b-instruct-bf16 • Confidence: MEDIUM

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Frequently Asked Questions
What is CVE-2021-38339?
The Simple Matted Thumbnails WordPress plugin is vulnerable to Reflected Cross-Site Scripting (XSS) due to improper handling of the $_SERVER['PHP_SELF'] variable in versions up to and including 1.01.
What is the CVSS score for CVE-2021-38339?
CVE-2021-38339 has CVSS 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS: 0.9%.
Is CVE-2021-38339 actively exploited?
No confirmed active exploitation of CVE-2021-38339 as of 2026-05-30.
How do I remediate CVE-2021-38339?
Priority: MEDIUM.
What systems are affected by CVE-2021-38339?
CVE-2021-38339 affects Devondev Simple Matted Thumbnails.
Vulnerability Details
CVE IDCVE-2021-38339
BSIDBS-2021-GLOBAL-304878-M BreachSpider Global ID
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Published2021-09-10
Last Modified2024-11-21
ICS Relevance0%
Weakness (CWE)
Cross-Site Scripting (XSS)
SourceNVD
Official Description

The Simple Matted Thumbnails WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to a reflected $_SERVER["PHP_SELF"] value in the ~/simple-matted-thumbnail.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.01.

Source: NIST NVD / MITRE CVE Database

Attack Vector Analysis — CITED Relevance

An attacker can inject arbitrary web scripts by manipulating the $_SERVER['PHP_SELF'] variable, which is then reflected back to the user without proper sanitization or encoding.

Exploitation Likelihood: MEDIUM

Affected Products
VendorProductAffected Versions
Devondev Simple Matted Thumbnails ≤ 1.01
Remediation

No official vendor advisory link on record. See the CVE record →

Threat Intelligence
● Threat Intelligence Validated: October 2026 | Threat Age: 1861 Days
CISA known-exploitedNot in KEV catalog
Public ExploitNot confirmed
PoC CodeNot confirmed
AI Enrichment Record — provenance & audit hash
Model/workspace/models/qwen2.5-coder-32b-instruct-bf16
ConfidenceMEDIUM
Enriched At2026-05-24
SHA-512 Audit Hash2bf9c058be3d5c3a77fbbf952003069a0a0e2a7a901f6338150868c3924bcf2fcb0374b8580b2202cb7e31a88bf548ea918e77a88c9a742bdb31e13cd51f4798

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