CVE-2014-7857

Public exploit available. Not confirmed exploited in the wild yet. A vendor fix is available.

CVSS 3.09.8Critical EPSS percentile97th15% chance in 30 days CISA KEVNot listedNo confirmed exploitation
Public exploit: 2 sources FixVendor fixNo build named by the sources

Published 2017-08-25Updated 2026-05-13Sources: CVE.org, NVD, BDU

NVD CVE.org

What to do

The vendor has published a fix. Version details are below where the sources state them.

D-link Dns-322l FirmwareAffected: ≤ 2.00b07Upgrade to: after 2.00b07Stated by: NVD
D-link Dns-325 FirmwareAffected: ≤ 1.05b03Upgrade to: after 1.05b03Stated by: NVD
D-link Dns-345 FirmwareAffected: ≤ 1.03b06Upgrade to: after 1.03b06Stated by: NVD
D-link Dns-320b FirmwareAffected: ≤ 1.02b01Upgrade to: after 1.02b01Stated by: NVD
D-link Dnr-326 FirmwareAffected: ≤ 1.40b03Upgrade to: after 1.40b03Stated by: NVD

Versions as the sources state them. 9 more products have version data. Full version matrix after sign-in

Steps

Written by AI from the record

Check the model and installed firmware version on every D-Link NAS or recorder you operate.
Update DNS-320L to firmware 1.04b12 or later, and DNS-327L to 1.03b04 Build0119 or later.
For DNR-326, DNS-320B, DNS-345, DNS-325, and DNS-322L, obtain the vendor-recommended replacement firmware or retirement guidance.
Until updated, remove the device’s management interface from internet access and restrict it to trusted local administrators.

Some work to apply

Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

D-Link DNS-320L firmware before 1.04b12, DNS-327L before 1.03b04 Build0119, DNR-326 1.40b03, DNS-320B 1.02b01, DNS-345 1.03b06, DNS-325 1.05b03, and DNS-322L 2.00b07 allow remote attackers to bypass authentication and log in with administrator permissions by passing the cgi_set_wto command in the cmd parameter, and setting the spawned session's cookie to username=admin.

In plain language

Written by AI from the record

D-Link NAS devices running affected firmware—including DNS-320L before 1.04b12 and DNS-327L before 1.03b04 Build0119—need attention because an outsider can take them over.

Unauthenticated network authentication bypass lets an attacker set an administrator session cookie after issuing a specific command, gaining full device administration.

If you're affected

Full device takeover
Stored file exposure
Data deletion risk
Ransomware risk
Backup service disruption

What is it

This is a flaw in the sign-in check for certain D-Link storage and recording devices. It is like a locked filing room whose door can be opened by presenting a forged staff badge: an outsider can become the device administrator and control the files and settings inside.

Who is affected

This matters if you run D-Link NAS firmware on a DNS-320L, DNS-327L, DNR-326, DNS-320B, DNS-345, DNS-325, or DNS-322L device. The listed affected releases can be reached over the network without a login or anyone clicking anything. It is especially relevant where the device management service is reachable from the internet.

How urgent is it

Public attack code is available, so an attacker can use this known route to attempt device takeover. Treat this as an amber priority: identify exposed affected devices promptly and restrict access while arranging the firmware update or replacement.

What to do — in detail

Inventory D-Link NAS and recorder appliances, identify each model, and record its installed firmware from the administrative interface.
Confirm exposure by determining whether the web administration service is reachable from the internet or untrusted internal networks; review firewall and router port-forwarding rules.
Upgrade DNS-320L to 1.04b12 or later and DNS-327L to 1.03b04 Build0119 or later. For DNR-326 1.40b03, DNS-320B 1.02b01, DNS-345 1.03b06, DNS-325 1.05b03, and DNS-322L 2.00b07, use the vendor remediation guidance to establish the supported update or replacement path; a clean fixed version is not provided in the findings.
If patching is delayed, remove external management access, allow administration only from a trusted management network, and disable unnecessary remote-access or port-forwarding rules.
Review device administrator accounts, network settings, file-sharing settings, and logs for unexpected changes or access. There is no CISA KEV remediation deadline because this CVE is not listed in KEV.

Technical context

CVE-2014-7857 is rated CVSS 9.8 Critical (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-287, improper authentication. The network-accessible flaw permits an unauthenticated attacker to invoke the cgi_set_wto command and set the resulting session cookie to username=admin, yielding administrative control. Two public exploits are known. It is not in CISA KEV; EPSS is 15.2% (97th percentile) and rising, which is a prediction rather than 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.

EPSS97th

Public exploit

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

2 sources with a proof of concept or module.

Exploit links, PoCs and Metasploit modules after sign-in

EPSS

15% chance of exploitation activity in the next 30 days, which ranks it in the 97th percentile of scored CVEs.

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

Lifecycle

A public exploit existed 67 days before the patch.

2026-09-22EPSS band change0 → moderateepss band change
2026-09-21EPSS band changemoderate → 0epss 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

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-287No name in the record

ATT&CK techniques

Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.

Initial AccessT1078Valid Accountshigh confidence T1190Exploit Public-Facing Applicationmedium confidence

Sources

References in the record

And 6 more references. See all after sign-in

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We'll flag the next CVE, public exploit or patch for Dns-322l Firmware, not every advisory. This one: public exploit.

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