How severe is CVE-2016-6380?

CVE-2016-6380 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2016-6380 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6380?

CVE-2016-6380 primarily affects Cisco Ios. In total, 3334 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6380?

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

When was CVE-2016-6380 published?

CVE-2016-6380 was published on 2016-10-05 and last updated on 2026-06-17.

CVE-2016-6380

CVE-2016-6380 is a high-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 8.1. 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-20.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v2: 8.3
EPSS exploit prediction: 3% (86th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cisco Ios
Published: 2016-10-05
Last modified: 2026-06-17

Description

The DNS forwarder in Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 3.1 through 3.15 allows remote attackers to obtain sensitive information from process memory or cause a denial of service (data corruption or device reload) via a crafted DNS response, aka Bug ID CSCup90532.

Frequently asked questions

What is CVE-2016-6380?: The DNS forwarder in Cisco IOS 12.0 through 12.4 and 15.0 through 15.6 and IOS XE 3.1 through 3.15 allows remote attackers to obtain sensitive information from process memory or cause a denial of service (data corruption or device reload) via a crafted DNS response, aka Bug ID CSCup90532.
How severe is CVE-2016-6380?: CVE-2016-6380 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2016-6380 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (86th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6380?: CVE-2016-6380 primarily affects Cisco Ios. In total, 3334 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6380?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2016-6380 published?: CVE-2016-6380 was published on 2016-10-05 and last updated on 2026-06-17.

References

Affected products (3334)

cpe:2.3:o:cisco:ios:12.0\(3\)t:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(3\)t1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(3\)t2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(3\)t3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(3\)xe:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(3\)xe1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(3\)xe2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(4\)t:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(4\)t1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(4\)xe:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(4\)xe1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(4\)xe2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)t:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)t1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)t2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe4:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe5:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe6:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe7:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xe8:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xk:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xk1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xk2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(5\)xt1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)t:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)t2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)t3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)xe1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)xe2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)xk:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)xk1:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)xk2:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.0\(7\)xk3:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.1\(1\):*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.1\(1\)e:*:*:*:*:*:*:*
cpe:2.3:o:cisco:ios:12.1\(1\)e1:*:*:*:*:*:*:*

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