VulnerabilityPublished 8 Dec 2025

CVE-2025-66334: Huawei HarmonyOS · Download of Code Without Integrity Check

Affects Huawei HarmonyOSSource CVE Database V5

Not known to be exploited · CVSS 3.3 Low.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

3.3Low

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

EPSS: 0.05% chance of exploitation in 30 days – higher than 0% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 8 Dec 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 26 Oct 2026.

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 or the CVSS exploit maturity 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

Affected software

Product	Affected	Fixed in
Huawei HarmonyOS	Affected =5.1.0 =5.0.1 =6.0.0	Fixed in–

AI-suggested

Restrict local access to devices running affected versions of HarmonyOS, ensuring only trusted users can interact with the office service.
Educate users to avoid downloading or opening untrusted files or code within the office service to reduce the risk of triggering the vulnerability.
Implement endpoint monitoring to detect abnormal crashes or service disruptions related to the office service.
Employ application whitelisting or integrity verification tools where possible to detect unauthorized code execution.
Maintain up-to-date backups and incident response plans to quickly recover from potential denial of service events.
Monitor Huawei security advisories for patches or updates addressing CVE-2025-66334 and apply them promptly once available.
Consider network segmentation to isolate HarmonyOS devices from critical infrastructure to limit potential impact.
Conduct regular security assessments focusing on local privilege escalation and social engineering vectors that could facilitate exploitation.

Description

Denial of service (DoS) vulnerability in the office service. Impact: Successful exploitation of this vulnerability may affect availability.

Impact

For European organizations, the primary impact is on availability of systems running Huawei HarmonyOS, particularly those utilizing the office service. Disruptions could affect productivity and business continuity, especially in environments where HarmonyOS devices are integrated into critical workflows. Although the vulnerability does not compromise data confidentiality or integrity, denial of service conditions can lead to downtime, loss of user trust, and potential operational delays. Organizations in sectors such as telecommunications, government, and enterprises with Huawei device deployments may face increased risk. The requirement for local access and user interaction reduces the likelihood of remote large-scale exploitation but insider threats or social engineering could still trigger the vulnerability. Given the growing adoption of Huawei technology in some European markets, the impact could be more pronounced in countries with higher market penetration. The absence of known exploits and patches currently limits immediate risk but also underscores the need for proactive monitoring and mitigation.

CWE-494Download of Code Without Integrity Check (opens in a new tab)
Base weaknessLikelihood of exploit: MediumOWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product downloads source code or an executable from a remote location and executes the code without sufficiently verifying the origin and integrity of the code.
Implementation
Perform proper forward and reverse DNS lookups to detect DNS spoofing.
Architecture and Design · Operation
Encrypt the code with a reliable encryption scheme before transmitting.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Docker Security (opens in a new tab)
XML Security (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
Infrastructure as Code (opens in a new tab)
OWASP ASVS 4.0.3
V1.14.2 (opens in a new tab)
V10.3.1 (opens in a new tab)
V13.3.2 (opens in a new tab)
Attack patterns
Malicious Software Download (opens in a new tab)
Malicious Software Update (opens in a new tab)
Malicious Automated Software Update via Redirection (opens in a new tab)
Malicious Manual Software Update (opens in a new tab)
Open-Source Library Manipulation (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

consumer.huawei.com/en/support/bulletin/2025/12/ (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 8 Dec 2025, 08:58 UTC

WeaknessesCWE-494

Technical details

References

Community reviews

Related threats