CVE-2015-7251

Public exploit available. Not confirmed exploited in the wild yet. No fix published yet.

CVSS 3.09.8Critical EPSS percentile96th11% chance in 30 days CISA KEVNot listedNo confirmed exploitation
Public exploit: 1 source FixNone yetNo fix or workaround published

Published 2015-12-30Updated 2026-05-06Sources: CVE.org, NVD

NVD CVE.org

What to do

No fixed build or workaround is published yet. Limit exposure and watch for a patch.

Steps

Written by AI from the record

Check whether you use a ZTE ZXHN H108N R1A router and identify its installed firmware version.
If it is before ZTE.bhs.ZXHNH108NR1A.k_PE, contact ZTE or your internet provider for a supported replacement or firmware update; no confirmed fixed version is available in the patch findings.
Disable TELNET access, especially from the internet, until the device is replaced or updated.
Change router administrator passwords and review its configuration for unfamiliar settings after securing access.

May need vendor or contractor work

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

ZTE ZXHN H108N R1A devices before ZTE.bhs.ZXHNH108NR1A.k_PE have a hardcoded password of root for the root account, which allows remote attackers to obtain administrative access via a TELNET session.

In plain language

Written by AI from the record

ZTE ZXHN H108N R1A firmware before ZTE.bhs.ZXHNH108NR1A.k_PE can let a network attacker take over the router, so affected businesses should act.

Unauthenticated network administrative access is possible because the device exposes a hardcoded root credential through TELNET.

If you're affected

Full router takeover
Internet traffic interception
Network service disruption
Malware entry point

What is it

This is a built-in administrator password that was left the same on affected routers. It is like installing a shop’s master lock with the key taped to the front door: someone who can reach the router may be able to take control of it.

Who is affected

This matters to you if you use or manage a ZTE ZXHN H108N R1A router. It is a risk only when the router runs an affected firmware version and its TELNET service is reachable from the network.

How urgent is it

Public attack code is available, so attackers do not need to develop this attack themselves. Treat this as an amber-priority issue: restrict TELNET access promptly and arrange a supported update or replacement, particularly for routers reachable from outside your business.

What to do — in detail

Confirm the model, installed firmware, and whether TELNET is enabled or reachable from internal networks or the internet. Firmware versions before ZTE.bhs.ZXHNH108NR1A.k_PE are affected; the available patch findings do not confirm a fixed release or supported upgrade path, so obtain guidance from ZTE, the ISP, or the device supplier before installing firmware.

If patching is delayed, disable TELNET or restrict it to a tightly controlled administrator network, block inbound TELNET at the firewall, and remove any internet exposure. Plan replacement if no supported firmware is available. Review router administration logs and configuration changes for unexpected administrator access, DNS changes, port-forwarding rules, or remote-management settings. CVE-2015-7251 is not listed in CISA KEV, so there is no CISA remediation due date.

Technical context

CVE-2015-7251 has CVSS 9.8 Critical (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H). It is CWE-255, involving a hardcoded credential for the root account exposed through TELNET; exploitation is network-based, requires no authentication or user interaction, and is reachable in the default configuration when TELNET is accessible. One public exploit is known. It is not in CISA KEV. EPSS predicts 10.7% likelihood (96th percentile) and is falling; this is a prediction, not confirmation of active exploitation.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS96th

Public exploit

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

1 source with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in

EPSS

11% chance of exploitation activity in the next 30 days, which ranks it in the 96th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Attention now

Rising.

Lifecycle

22 events over 3920 days, from the signal feeds we watch.

2026-09-23EPSS band changelow → moderateepss band change
2026-09-21EPSS band changemoderate → lowepss band change
2026-09-06EPSS band change0 → moderateepss band change
2026-09-05EPSS band changemoderate → 0epss band change
2026-08-31EPSS band change0 → moderateepss band change
2026-08-29EPSS band changemoderate → low

Affected products

ztecommercial · CNaka zte corporation
- zxhn h108n r1a firmwareNetworking Infrastructure

And 1 more affected product. See all after sign-in

Technical detail

CVSS 3.0 vector

Open in the CVSS calculator

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Scored 9.8 by NVD.

How it is reached

Attack Vector NetworkExploitable remotely over the network without any special conditions
Attack Complexity LowNo special conditions — the attack can be reliably reproduced
Privileges Required NoneNo authentication required — anyone can exploit this
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality HighTotal information disclosure — all data in the component is compromised
Integrity HighTotal loss of integrity — attacker can modify any data in the component
Availability HighTotal denial of service — the component is completely unavailable

Weaknesses

CWE-255No name in the record

Sources

References in the record

And 1 more reference. See all after sign-in

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We'll flag the next CVE, public exploit or patch for Zxhn H108n R1a Firmware, not every advisory. This one: public exploit.

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