CVE-2025-4424VulnerabilityPublished 30 Jul 2025Updated 14 Aug 2025

CVE-2025-4424: Insyde Software InsydeH2O · Improper Input Validation

Affects Insyde Software InsydeH2OSource CVE Database V5

Not known to be exploited · CVSS 6.0 Medium.

Data as of 26 Oct 2026, 07:57 UTC

CVSS 3.1 base score

6.0Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

Attack Vector: Local
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 30 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

AI-suggested

European organizations should implement a multi-layered approach to mitigate this vulnerability effectively. First, they must inventory all Lenovo devices running InsydeH2O firmware and verify if they include the affected feature. Regularly monitor Lenovo's official Product Security Advisories for patches or firmware updates addressing CVE-2025-4424 and apply them promptly once available. Until patches are released, restrict local administrative access to trusted personnel only and enforce strict privilege management policies to minimize the risk of exploitation. Employ endpoint detection and response (EDR) solutions capable of monitoring firmware integrity and detecting anomalous behavior indicative of firmware tampering. Additionally, enable and enforce secure boot and trusted platform module (TPM) features to help detect unauthorized firmware modifications. Conduct regular security awareness training to reduce insider threat risks and implement robust physical security controls to prevent unauthorized local access. Finally, consider deploying firmware scanning tools that can detect known vulnerabilities or unauthorized changes in BIOS/UEFI firmware versions.

Description

The vulnerability was identified in the code developed specifically for Lenovo. Please visit "Lenovo Product Security Advisories and Announcements" webpage for more information about the vulnerability. https://support.lenovo.com/us/en/product_security/home

Impact

For European organizations, this vulnerability poses a significant risk, especially for enterprises and governmental bodies relying on Lenovo hardware with InsydeH2O firmware. A successful exploit could allow attackers with local high privileges to escalate their control over the firmware, undermining system integrity and enabling stealthy persistence mechanisms. This could facilitate espionage, sabotage, or data manipulation without detection by traditional security controls. The scope change means that attackers could potentially affect other system components or firmware modules, increasing the attack surface. Given the critical nature of firmware in securing the boot process and hardware trust anchors, exploitation could compromise endpoint security solutions, encryption keys, and secure boot mechanisms. This is particularly concerning for sectors with high security requirements such as finance, defense, and critical infrastructure within Europe. Although exploitation requires local access with high privileges, insider threats or attackers who have already breached perimeter defenses could leverage this vulnerability to deepen their foothold. The absence of known exploits currently provides a window for proactive mitigation, but organizations must act swiftly to prevent future exploitation.

Summary

CVE-2025-4424 is a medium-severity vulnerability classified under CWE-20, which pertains to improper input validation. This vulnerability exists in the InsydeH2O firmware developed by Insyde Software, specifically in a feature tailored for Lenovo devices. Improper input validation flaws occur when software does not adequately check or sanitize input data, potentially allowing attackers to manipulate the program's behavior. In this case, the vulnerability affects the BIOS/UEFI firmware layer, which is critical for system initialization and security. According to the CVSS 3.1 vector (AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:H/A:N), exploitation requires local access with high privileges, no user interaction, and results in a scope change. The impact is high on integrity but does not affect confidentiality or availability. The scope change indicates that the vulnerability allows an attacker to affect resources beyond their initial privileges, potentially compromising the firmware's integrity or enabling persistent malicious modifications. While no known exploits are currently in the wild, the vulnerability's presence in firmware means that successful exploitation could lead to persistent compromise that survives OS reinstallations or disk replacements. The lack of publicly available patches at the time of publication suggests that affected organizations should monitor Lenovo's security advisories closely for updates. Given the firmware's critical role, this vulnerability could be leveraged for advanced persistent threats or targeted attacks against Lenovo hardware platforms.

CWE-20Improper Input Validation (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #18OWASP Top 10 A05:2025: Injection (opens in a new tab)
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Attack Surface Reduction
Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build "recognizers" for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of…
Architecture and Design · Libraries or Frameworks
Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
Architecture and Design · Implementation · Attack Surface Reduction
Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any…
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
Injection Prevention (opens in a new tab)
SQL Injection Prevention (opens in a new tab)
Injection Prevention in Java (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
Attack patterns
Buffer Overflow via Environment Variables (opens in a new tab)
Server Side Include (SSI) Injection (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Command Line Execution through SQL Injection (opens in a new tab)
Object Relational Mapping Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 15 Aug 2025, 00:47 UTC

WeaknessesCWE-20

Technical details

References

Community reviews

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