Cyber Resilience

CVE-2025-25477

HighPublic PoC

Published: 28 February 2025

Published
28 February 2025
Modified
09 July 2025
KEV Added
Patch
CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
EPSS Score 0.0012 30.8th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-25477 is a high-severity Injection (CWE-74) vulnerability in Syspass Syspass. Its CVSS base score is 8.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 30.8th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).

Deeper analysis

CVE-2025-25477 is a host header injection vulnerability in SysPass 3.2x. Published on 2025-02-28, it enables an attacker to load malicious JavaScript files from an arbitrary domain, which are subsequently executed in the victim's browser. The issue carries a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N) and maps to CWE-74 (Improper Neutralization of Special Elements in Output).

An unauthenticated attacker can exploit this over the network with low attack complexity, though it requires user interaction such as a victim accessing a crafted link or page. By injecting a malicious host header, the attacker causes SysPass to fetch and execute arbitrary JavaScript in the victim's browser context, achieving high impacts on confidentiality and integrity, such as stealing sensitive data, session tokens, or performing further client-side attacks.

Mitigation details are available in the referenced advisory at https://github.com/sysentr0py/CVEs/tree/main/CVE-2025-25477.

EU & UK References

Vulnerability details

A host header injection vulnerability in SysPass 3.2x allows an attacker to load malicious JS files from an arbitrary domain which would be executed in the victim's browser.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access
Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.
T1059.007 JavaScript Execution
Adversaries may abuse various implementations of JavaScript for execution.
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.
T1555.003 Credentials from Web Browsers Credential Access
Adversaries may acquire credentials from web browsers by reading files specific to the target browser.
Why these techniques?

Host header injection enables SysPass to serve malicious JS from attacker-controlled domains, facilitating drive-by compromise (T1189), JavaScript execution (T1059.007), session cookie theft (T1539), and credential theft from web browsers/password manager context (T1555.003).

CVEs Like This One

CVE-2026-25520Shared CWE-74
CVE-2026-29053Shared CWE-74
CVE-2026-25586Shared CWE-74
CVE-2024-39604Shared CWE-74
CVE-2025-20337Shared CWE-74
CVE-2026-42334Shared CWE-74
CVE-2025-67733Shared CWE-74
CVE-2026-2469Shared CWE-74
CVE-2026-22200Shared CWE-74
CVE-2025-64428Shared CWE-74

Affected Assets

syspass
syspass
3.2.0 — 3.2.11

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

prevent

Validates HTTP host headers to block injection of arbitrary domains that lead to loading malicious JavaScript in the victim's browser.

prevent

Filters outputs containing host-derived values in script sources to neutralize special elements and prevent execution of injected malicious JavaScript.

prevent

Remediates the specific host header injection flaw in SysPass 3.2x through timely patching and testing of software updates.

References