What is CVE-2021-27852?

CVE-2021-27852 is a critical-severity vulnerability in Checkbox Survey, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2021-05-27.

How severe is CVE-2021-27852?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2021-27852 known to be exploited?

Yes. CVE-2021-27852 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-04-11), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.

Deserialization in Checkbox Survey

CVE-2021-27852

Deserialization of Untrusted Data vulnerability in CheckboxWeb.dll of Checkbox Survey allows an unauthenticated remote attacker to execute arbitrary code. This issue affects: Checkbox Survey versions prior to 7.

Vulnerability class: Insecure Deserialization

EPSS: 0.319 (98.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Checkbox Survey — versions unspecified

Weakness classification (CWE)

CWE-502 — Deserialization of Untrusted Data

CISA KEV (Known Exploited Vulnerabilities)

This CVE is on the CISA KEV catalog, added on 2022-04-11. CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.

BOD 22-01 due date: 2022-05-02.

Required action: 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.

Public proof-of-concept exploits

References

cret@cert.org (US Government Resource, Third Party Advisory)
134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)

Frequently asked questions

What is CVE-2021-27852?: CVE-2021-27852 is a critical-severity vulnerability in Checkbox Survey, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2021-05-27.
How severe is CVE-2021-27852?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-27852 known to be exploited?: Yes. CVE-2021-27852 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2022-04-11), indicating it is being actively exploited. 4 public proof-of-concept repositories are indexed.