How severe is CVE-2016-6603?

CVE-2016-6603 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-2016-6603 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 87% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6603?

CVE-2016-6603 primarily affects Zohocorp Webnms Framework. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6603?

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-2016-6603 published?

CVE-2016-6603 was published on 2017-01-23 and last updated on 2026-06-17.

CVE-2016-6603

CVE-2016-6603 is a critical-severity vulnerability in Zohocorp Webnms Framework with a CVSS 3.x base score of 9.8. Its EPSS exploit-prediction score of 87% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.8)
CVSS v2: 5.0
EPSS exploit prediction: 87% (100th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Zohocorp Webnms Framework
Published: 2017-01-23
Last modified: 2026-06-17

Description

ZOHO WebNMS Framework 5.2 and 5.2 SP1 allows remote attackers to bypass authentication and impersonate arbitrary users via the UserName HTTP header.

Frequently asked questions

What is CVE-2016-6603?: ZOHO WebNMS Framework 5.2 and 5.2 SP1 allows remote attackers to bypass authentication and impersonate arbitrary users via the UserName HTTP header.
How severe is CVE-2016-6603?: CVE-2016-6603 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-2016-6603 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 87% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6603?: CVE-2016-6603 primarily affects Zohocorp Webnms Framework. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6603?: 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-2016-6603 published?: CVE-2016-6603 was published on 2017-01-23 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:zohocorp:webnms_framework:5.2:*:*:*:*:*:*:*
cpe:2.3:a:zohocorp:webnms_framework:5.2:sp1:*:*:*:*:*:*

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