Is CVE-2021-27852 actively exploited?

Yes. CVE-2021-27852 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2021-27852 be exploited remotely?

The attack vector of CVE-2021-27852 has not been classified yet.

What is the CVSS score of CVE-2021-27852?

CVE-2021-27852 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2021-27852

HIGHCISA KEVIN THE WILD

CVE-2021-27852

Published: April 11, 2022

EPSS:25.55%probability of exploitation in 30 daysPercentile:96.1th

Official Description

Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code.

NVD Source

CISA KEV Advisory

Checkbox Survey Deserialization of Untrusted Data Vulnerability

Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code.

Added to KEV: 2022-04-11Federal patch deadline: 2022-05-02

Required Action (CISA)

Versions 6 and earlier for this product are end-of-life and must be removed from agency networks. Versions 7 and later are not considered vulnerable.

Risk Analysis

This high-severity deserialization vulnerability in Checkbox Survey's CheckboxWeb.dll allows an unauthenticated remote attacker to execute arbitrary code. With confirmed exploitation in the wild and an EPSS score of 0.25548, this flaw poses a critical and urgent risk, allowing full system compromise. Administrators must address this immediately.

Active exploitation of this vulnerability has been observed in the wild, and it is included in CISA's KEV catalog. The flaw is remotely exploitable without authentication.

Recommended Action

Apply all available security updates for Checkbox Survey. Implement secure deserialization practices and ensure proper input validation to prevent arbitrary code execution.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2021-27852 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2021-27852 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.