What is the CVSS score of CVE-2021-39307?

CVE-2021-39307 has a CVSS 3.1 base score of 6.1 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N. EPSS exploitation probability: 1.1%.

Is there a public PoC exploit available for CVE-2021-39307?

Yes, a public proof-of-concept exploit is available for CVE-2021-39307. Prioritise patching immediately. EPSS: 1.1%.

Webviewer Ui CVE-2021-39307

MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2021-09-15 cve@mitre.org

XSS Webviewer Ui

6.1

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

6.1 MEDIUM

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

CVE Published

Sep 15, 2021 - 13:15 nvd

MEDIUM 6.1

DescriptionNVD

PDFTron's WebViewer UI 8.0 or below renders dangerous URLs as hyperlinks in supported documents, including JavaScript URLs, allowing the execution of arbitrary JavaScript code.

AnalysisAI

PDFTron's WebViewer UI 8.0 or below renders dangerous URLs as hyperlinks in supported documents, including JavaScript URLs, allowing the execution of arbitrary JavaScript code. Rated medium severity (CVSS 6.1), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available and no vendor patch available.

Technical ContextAI

This vulnerability is classified as Cross-Site Scripting (XSS) (CWE-79), which allows attackers to inject malicious scripts into web pages viewed by other users. PDFTron's WebViewer UI 8.0 or below renders dangerous URLs as hyperlinks in supported documents, including JavaScript URLs, allowing the execution of arbitrary JavaScript code. Affected products include: Pdftron Webviewer Ui.

RemediationAI

No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Sanitize all user input, use Content-Security-Policy headers, encode output contextually (HTML, JS, URL). Use frameworks with built-in XSS protection.