How severe is CVE-2020-3420?

CVE-2020-3420 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2020-3420 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-3420?

CVE-2020-3420 affects Cisco Unified Communications Manager. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-3420?

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

Does CVE-2020-3420 have an EU (EUVD) identifier?

Yes. CVE-2020-3420 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-24691.

When was CVE-2020-3420 published?

CVE-2020-3420 was published on 2024-11-18 and last updated on 2026-06-17.

CVE-2020-3420

CVE-2020-3420 is a medium-severity vulnerability in Cisco Unified Communications Manager with a CVSS 3.x base score of 5.4. 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-79.

Key facts

Severity: Medium (CVSS 3.x base score 5.4)
EPSS exploit prediction: 0% (32nd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2020-24691
Weakness: CWE-79
Affected product: Cisco Unified Communications Manager
Published: 2024-11-18
Last modified: 2026-06-17

Description

A vulnerability in the web-based management interface of Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected software. An attacker could exploit this vulnerability by inserting malicious data into a specific data field in the interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive browser-based information.There are no workarounds that address this vulnerability.

Frequently asked questions

What is CVE-2020-3420?: A vulnerability in the web-based management interface of Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the interface. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of the affected software. An attacker could exploit this vulnerability by inserting malicious data into a specific data field in the interface. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive browser-based information.There are no workarounds that address this vulnerability.
How severe is CVE-2020-3420?: CVE-2020-3420 has a CVSS 3.x base score of 5.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2020-3420 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (32nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-3420?: CVE-2020-3420 affects Cisco Unified Communications Manager. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-3420?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2020-3420 have an EU (EUVD) identifier?: Yes. CVE-2020-3420 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2020-24691.
When was CVE-2020-3420 published?: CVE-2020-3420 was published on 2024-11-18 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:*:*:*:*

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