Cyber Resilience

CVE-2025-56515

HighPublic PoC

Published: 01 October 2025

Published
01 October 2025
Modified
15 October 2025
KEV Added
Patch
CVSS Score v3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS Score 0.0004 11.3th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-56515 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Suisuijiang Fiora. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique SVG Smuggling (T1027.017); ranked at the 11.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

File upload vulnerability in Fiora chat application 1.0.0 through user avatar upload functionality. The application fails to validate SVG file content, allowing malicious SVG files with embedded foreignObject elements containing iframe tags and JavaScript event handlers (onmouseover) to be uploaded…

more

and stored. When rendered, these SVG files execute arbitrary JavaScript, enabling attackers to steal user sessions, cookies, and perform unauthorized actions in the context of users viewing affected profiles.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1027.017 SVG Smuggling Stealth
Adversaries may smuggle data and files past content filters by hiding malicious payloads inside of seemingly benign SVG files.
T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
T1550.004 Web Session Cookie Lateral Movement
Adversaries can use stolen session cookies to authenticate to web applications and services.
T1539 Steal Web Session Cookie Credential Access
An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.
Why these techniques?

The vulnerability allows uploading malicious SVGs smuggling JavaScript payloads (T1027.017) that execute in victims' browsers (T1059.007) to steal web session cookies (T1506, T1539).

Affected Assets

suisuijiang
fiora
1.0.0

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-79

Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.

addresses: CWE-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

addresses: CWE-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

addresses: CWE-79

Validates web inputs to reject script-related content that could produce XSS.

addresses: CWE-79

Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.

addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

References