XSS in Cisco Firepower Management Center

CVE-2021-1239

Multiple vulnerabilities in the web-based management interface of Cisco Firepower Management Center (FMC) could allow an authenticated, remote attacker to conduct a stored cross-site scripting (XSS) attack against a user of the interface of an affected system. The vulnerabilities exist because the web-based management interface does not properly validate user-supplied input. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. 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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.006 (45.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.8 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-1239?
CVE-2021-1239 is a medium-severity vulnerability in Cisco Firepower Management Center, classified under Cross-site Scripting. CVSS score: 4.8/10. Published 2021-01-13.
How severe is CVE-2021-1239?
Medium severity. CVSS v3 base score is 4.8 out of 10.
Is CVE-2021-1239 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.