Page generated: 09 Nov 2026, 09:59 UTC
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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.

CVSS 9.8 (CRITICAL) KEV: KNOWN CATALOG

Attention and evidence

HYPE SCORE
0.0/10
REALITY · THREAT PRIORITY
8.6/10
General review priority; not probability

Evidence confidence: Exploitation recorded

Why this priority?
  • Recorded exploitation baseline: +7.00
  • Technical severity: CVSS 9.8: +1.47
  • Fresh EPSS: 30.26%: +0.15

General review priority, not probability, victim count or asset-specific risk. A range covers missing CVSS/EPSS inputs within the current evidence state.

Sources: 3 documents and public datasets.

Hype components

Headline sample (25%)
0/100
Press, 30 days (60%)
0/100
Grounded branding (15%)
0/100
HYPE TOTAL0/100

Sources and documents

BleepingComputer
Press · 20 Sep 2021, 07:00 · Hacked sites push TeamViewer using fake expired certificate alert - BleepingComputer
The Hacker News
Press · 02 Aug 2021, 07:00 · New APT Hacking Group Targets Microsoft IIS Servers with ASP.NET Exploits - The Hacker News
The Record from Recorded Future News
Press · 26 Jul 2021, 07:00 · Praying Mantis APT targets IIS servers with ASP.NET exploits - The Record from Recorded Future News

Score evolution

● Hype   ● Reality

Earlier evidence-support scores are retained in history; this chart shows only the current priority definition.

First record: hype 0.0 · reality 8.6 (2026-11-02 15:12). The curve appears once the score changes.

Public exploit evidence

0

Public exploit entries / repo candidates

Evidence context and dated references

Reality is general threat/review priority, combining observed exploitation, CVSS severity and fresh EPSS. Evidence confidence is separate. This is not calibrated risk, a victim count or an asset-specific assessment. A range reflects missing numeric inputs.

Evidence in context

Confidence in exploitation evidence
Exploitation recorded
Priority basis
Recorded exploitation; CVSS 9.8; EPSS 30.3%
Attention, last 30 days
0 distinct story titles; 0 press documents; 0 publisher domains.
Technical potential
network access, no prior privileges, no user interaction.
Observed activity
Exploitation recorded in CISA KEV.
Known scale
Not quantified.
Evidence confidence basis
Trusted exploitation confirmation

Score evaluated: 2026-11-05 13:58:25.853394+00:00 · EPSS snapshot: 2026-11-05T12:03:04Z

Source event timeline
Published
27 May 2021, 20:55
First press mention
26 Jul 2021, 07:00
Latest press mention
20 Sep 2021, 07:00
Added to the CISA KEV catalog
11 Apr 2022, 00:00
Score calculated
05 Nov 2026, 13:58