How severe is CVE-2015-6016?

CVE-2015-6016 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2015-6016 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2015-6016?

CVE-2015-6016 primarily affects Zyxel Nbg-418n. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2015-6016?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2015-6016 published?

CVE-2015-6016 was published on 2015-12-31 and last updated on 2026-06-17.

CVE-2015-6016

CVE-2015-6016 is a critical-severity vulnerability in Zyxel Nbg-418n with a CVSS 3.x base score of 9.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-255.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 10.0
EPSS exploit prediction: 6% (92nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-255
Affected product: Zyxel Nbg-418n
Published: 2015-12-31
Last modified: 2026-06-17

Description

ZyXEL P-660HW-T1 2 devices with ZyNOS firmware 3.40(AXH.0), PMG5318-B20A devices with firmware 1.00AANC0b5, and NBG-418N devices have a default password of 1234 for the admin account, which allows remote attackers to obtain administrative access via unspecified vectors.

Frequently asked questions

What is CVE-2015-6016?: ZyXEL P-660HW-T1 2 devices with ZyNOS firmware 3.40(AXH.0), PMG5318-B20A devices with firmware 1.00AANC0b5, and NBG-418N devices have a default password of 1234 for the admin account, which allows remote attackers to obtain administrative access via unspecified vectors.
How severe is CVE-2015-6016?: CVE-2015-6016 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2015-6016 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 6% (92nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2015-6016?: CVE-2015-6016 primarily affects Zyxel Nbg-418n. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2015-6016?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2015-6016 published?: CVE-2015-6016 was published on 2015-12-31 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:h:zyxel:nbg-418n:-:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:zynos_firmware:3.40$axh.0$:*:*:*:*:*:*:*
cpe:2.3:o:zyxel:pmg5318-b20a_firmware:v100aanc0b5:*:*:*:*:*:*:*

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