How severe is CVE-2016-6420?

CVE-2016-6420 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2016-6420 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6420?

CVE-2016-6420 primarily affects Cisco Firesight System Software. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6420?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2016-6420 published?

CVE-2016-6420 was published on 2016-10-05 and last updated on 2026-06-17.

CVE-2016-6420

CVE-2016-6420 is a medium-severity vulnerability in Cisco Firesight System Software with a CVSS 3.x base score of 6.5. 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-200.

Key facts

Severity: Medium (CVSS 3.x base score 6.5)
CVSS v2: 6.8
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-200
Affected product: Cisco Firesight System Software
Published: 2016-10-05
Last modified: 2026-06-17

Description

Cisco FireSIGHT System Software 4.10.3 through 5.4.0 in Firepower Management Center allows remote authenticated users to bypass authorization checks and gain privileges via a crafted HTTP request, aka Bug ID CSCur25467.

Frequently asked questions

What is CVE-2016-6420?: Cisco FireSIGHT System Software 4.10.3 through 5.4.0 in Firepower Management Center allows remote authenticated users to bypass authorization checks and gain privileges via a crafted HTTP request, aka Bug ID CSCur25467.
How severe is CVE-2016-6420?: CVE-2016-6420 has a CVSS 3.x base score of 6.5, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2016-6420 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6420?: CVE-2016-6420 primarily affects Cisco Firesight System Software. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6420?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2016-6420 published?: CVE-2016-6420 was published on 2016-10-05 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:cisco:firesight_system_software:4.10.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firesight_system_software:5.2.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firesight_system_software:5.3.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firesight_system_software:5.3.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:firesight_system_software:5.4.0:*:*:*:*:*:*:*

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