How severe is CVE-2021-1399?

CVE-2021-1399 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-1399 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1399?

CVE-2021-1399 primarily affects Cisco Unified Communications Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1399?

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

When was CVE-2021-1399 published?

CVE-2021-1399 was published on 2021-04-08 and last updated on 2026-06-17.

CVE-2021-1399

CVE-2021-1399 is a medium-severity vulnerability in Cisco Unified Communications Manager with a CVSS 3.x base score of 4.3. 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-302.

Key facts

Severity: Medium (CVSS 3.x base score 4.3)
CVSS v2: 4.0
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-302
Affected product: Cisco Unified Communications Manager
Published: 2021-04-08
Last modified: 2026-06-17

Description

A vulnerability in the Self Care Portal 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 modify data on an affected system without proper authorization. The vulnerability is due to insufficient validation of user-supplied data to the Self Care Portal. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected system. A successful exploit could allow the attacker to modify information without proper authorization.

Frequently asked questions

What is CVE-2021-1399?: A vulnerability in the Self Care Portal 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 modify data on an affected system without proper authorization. The vulnerability is due to insufficient validation of user-supplied data to the Self Care Portal. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected system. A successful exploit could allow the attacker to modify information without proper authorization.
How severe is CVE-2021-1399?: CVE-2021-1399 has a CVSS 3.x base score of 4.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-1399 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1399?: CVE-2021-1399 primarily affects Cisco Unified Communications Manager. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1399?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1399 published?: CVE-2021-1399 was published on 2021-04-08 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cucm-selfcare-VRWWWHgE

Affected products (2)

cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:-:*:*:*
cpe:2.3:a:cisco:unified_communications_manager:*:*:*:*:session_management:*:*:*

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