How severe is CVE-2021-1582?

CVE-2021-1582 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-2021-1582 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-1582?

CVE-2021-1582 primarily affects Cisco Application Policy Infrastructure Controller. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-1582?

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

When was CVE-2021-1582 published?

CVE-2021-1582 was published on 2021-08-25 and last updated on 2026-06-17.

CVE-2021-1582

CVE-2021-1582 is a medium-severity vulnerability in Cisco Application Policy Infrastructure Controller 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)
CVSS v2: 3.5
EPSS exploit prediction: 1% (44th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-79
Affected product: Cisco Application Policy Infrastructure Controller
Published: 2021-08-25
Last modified: 2026-06-17

Description

A vulnerability in the web UI of Cisco Application Policy Infrastructure Controller (APIC) or Cisco Cloud APIC could allow an authenticated, remote attacker to perform a stored cross-site scripting attack on an affected system. This vulnerability is due to improper input validation in the web UI. An authenticated attacker could exploit this vulnerability by sending malicious input to the web UI. A successful exploit could allow the attacker to execute arbitrary script code in the context of the web-based interface or access sensitive, browser-based information.

Frequently asked questions

What is CVE-2021-1582?: A vulnerability in the web UI of Cisco Application Policy Infrastructure Controller (APIC) or Cisco Cloud APIC could allow an authenticated, remote attacker to perform a stored cross-site scripting attack on an affected system. This vulnerability is due to improper input validation in the web UI. An authenticated attacker could exploit this vulnerability by sending malicious input to the web UI. A successful exploit could allow the attacker to execute arbitrary script code in the context of the web-based interface or access sensitive, browser-based information.
How severe is CVE-2021-1582?: CVE-2021-1582 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-2021-1582 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (44th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1582?: CVE-2021-1582 primarily affects Cisco Application Policy Infrastructure Controller. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1582?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-1582 published?: CVE-2021-1582 was published on 2021-08-25 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-capic-scss-bFT75YrM

Affected products (2)

cpe:2.3:a:cisco:application_policy_infrastructure_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:cisco:cloud_application_policy_infrastructure_controller:*:*:*:*:*:*:*:*

More vulnerabilities in Cisco Application Policy Infrastructure Controller

CVE-2021-1388 — Critical (CVSS 10.0): A vulnerability in an API endpoint of Cisco ACI Multi-Site Orchestrator (MSO) installed on the Application Services…
CVE-2021-1396 — Critical (CVSS 9.8): Multiple vulnerabilities in Cisco Application Services Engine could allow an unauthenticated, remote attacker to gain…
CVE-2021-1393 — Critical (CVSS 9.8): Multiple vulnerabilities in Cisco Application Services Engine could allow an unauthenticated, remote attacker to gain…
CVE-2021-1577 — Critical (CVSS 9.1): A vulnerability in an API endpoint of Cisco Application Policy Infrastructure Controller (APIC) and Cisco Cloud…
CVE-2023-20011 — High (CVSS 8.8): A vulnerability in the web-based management interface of Cisco Application Policy Infrastructure Controller (APIC) and…
CVE-2021-1578 — High (CVSS 8.8): A vulnerability in an API endpoint of Cisco Application Policy Infrastructure Controller (APIC) and Cisco Cloud…

All CVEs affecting Cisco Application Policy Infrastructure Controller →

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

CVE-2025-49410 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Imran Emu TC…
CVE-2024-47875 — Critical (CVSS 10.0): DOMPurify is a DOM-only, super-fast, uber-tolerant XSS sanitizer for HTML, MathML and SVG. DOMpurify was vulnerable to…
CVE-2024-6886 — Critical (CVSS 10.0): Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Gitea…
CVE-2023-45144 — Critical (CVSS 10.0): com.xwiki.identity-oauth:identity-oauth-ui is a package to aid in building identity and service providers based on…
CVE-2023-45138 — Critical (CVSS 10.0): Change Request is an pplication allowing users to request changes on a wiki without publishing the changes directly.…
CVE-2022-4361 — Critical (CVSS 10.0): Keycloak, an open-source identity and access management solution, has a cross-site scripting (XSS) vulnerability in the…

Browse all CWE-79 (Cross-site Scripting (XSS)) vulnerabilities →