CVE-2021-1531

CVE-2021-1531 is a high-severity vulnerability in Cisco Modeling Labs with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 30% places it in the 98th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-88.

Key facts

Description

A vulnerability in the web UI of Cisco Modeling Labs could allow an authenticated, remote attacker to execute arbitrary commands with the privileges of the web application on the underlying operating system of an affected Cisco Modeling Labs server. This vulnerability is due to insufficient validation of user-supplied input to the web UI. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected server. A successful exploit could allow the attacker to execute arbitrary commands with the privileges of the web application, virl2, on the underlying operating system of the affected server. To exploit this vulnerability, the attacker must have valid user credentials on the web UI.

Frequently asked questions

What is CVE-2021-1531?
A vulnerability in the web UI of Cisco Modeling Labs could allow an authenticated, remote attacker to execute arbitrary commands with the privileges of the web application on the underlying operating system of an affected Cisco Modeling Labs server. This vulnerability is due to insufficient validation of user-supplied input to the web UI. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected server. A successful exploit could allow the attacker to execute arbitrary commands with the privileges of the web application, virl2, on the underlying operating system of the affected server. To exploit this vulnerability, the attacker must have valid user credentials on the web UI.
How severe is CVE-2021-1531?
CVE-2021-1531 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-1531 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 30% (98th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-1531?
CVE-2021-1531 primarily affects Cisco Modeling Labs. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-1531?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-1531 published?
CVE-2021-1531 was published on 2021-05-22 and last updated on 2026-06-17.

References

Affected products (6)

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