CVE-2025-29525VulnerabilityPublished 25 Aug 2025Updated 26 Aug 2025

CVE-2025-29525: n/a

Source CVE Database V5

Not known to be exploited · CVSS 5.3 Medium.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score

5.3Medium

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

EPSS: 0.2% chance of exploitation in 30 days – higher than 21% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
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: None: The vulnerable system can be exploited without any interaction from any user.
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: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within 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 25 Aug 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

To mitigate this vulnerability effectively, European organizations and ISPs should take the following specific actions: 1) Immediately audit all DASAN GPON ONU H660WM devices in their networks to identify units running the affected OS and hardware versions. 2) Change all default credentials on these devices to strong, unique passwords that comply with organizational password policies. 3) Implement network segmentation to isolate GPON ONU devices from critical internal systems, limiting the potential impact of any compromise. 4) Restrict management interface access to trusted IP addresses or management VLANs only, preventing unauthorized remote access. 5) Monitor network traffic for unusual access patterns or attempts to connect to the control panel interfaces of these devices. 6) Engage with DASAN or device vendors to obtain firmware updates or patches addressing this vulnerability once available, and plan for timely deployment. 7) Educate network administrators and field technicians about the risks of default credentials and enforce procedures to change them during device provisioning. 8) Consider deploying intrusion detection or prevention systems capable of identifying attempts to exploit default credential vulnerabilities on network devices.

Description

DASAN GPON ONU H660WM OS version H660WMR210825 Hardware version DS-E5-583-A1 was discovered to contain insecure default credentials in the modem's control panel.

Impact

For European organizations, the presence of insecure default credentials in widely deployed GPON ONU devices poses a risk primarily to confidentiality. Attackers who gain network access to these devices could harvest sensitive configuration information or network details, which could be leveraged for further attacks such as network reconnaissance or lateral movement. Although the vulnerability does not directly affect integrity or availability, the exposure of sensitive information could facilitate targeted attacks against organizational infrastructure. In environments where these devices are deployed at scale, such as ISPs serving European customers or enterprises using these modems for fiber connectivity, the risk is amplified. Additionally, compromised devices could be used as entry points into internal networks if proper network segmentation is not enforced. The lack of required authentication or user interaction makes exploitation easier for remote attackers with network access. However, the medium severity rating reflects the limited scope of impact. The absence of known exploits in the wild suggests that exploitation is not yet widespread, but the vulnerability should be addressed proactively to prevent potential abuse.

CWE-1392Use of Default Credentials (opens in a new tab)
Base weaknessOWASP Top 10 A07:2025: Authentication Failures (opens in a new tab)
The product uses default credentials (such as passwords or cryptographic keys) for potentially critical functionality.
Requirements
Prohibit use of default, hard-coded, or other values that do not vary for each installation of the product - especially for separate organizations.
Architecture and Design
Force the administrator to change the credential upon installation.
Installation · Operation
The product administrator could change the defaults upon installation or during operation.
OWASP Cheat Sheets
OWASP Authentication (opens in a new tab)
OWASP ASVS 4.0.3
V2.8.5 (opens in a new tab)
V2.8.4 (opens in a new tab)
V9.2.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

gist.github.com/stevenyu113228/20ecc24a10e2b1b7038634b838503d7c (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Description

AI analysisMachine-generated, updated 2 Sep 2025, 01:07 UTC

WeaknessesCWE-1392

Technical details

References

Community reviews

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