CVE-2021-32847 | Moby HyperKit uninitialized memory use in virtio-sock pci_vtsock_proc_tx

Exp

HyperKit is a toolkit for embedding hypervisor capabilities in an application. In versions 0.20210107 and prior, a malicious guest can trigger a vulnerability in the host by abusing the disk driver that may lead to the disclosure of the host memory into the virtualized guest. This issue is fixed in commit cf60095a4d8c3cb2e182a14415467afd356e982f.

Published: 2023-02-20 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-32847 is rated Exploit Available (53.7/100): CVSS High severity, with low exploitation likelihood (EPSS 0.37%). 2 public exploit reference(s) are indexed (Exploit-DB). Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-32847

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-32847

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.37% +0.34%
2 2026-03-02 0.10% 0.03% -0.07%
3 2025-03-30 — 0.10% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-32847

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.1 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.5 4.0 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.0 4.0 [email protected]

Weakness enumeration for CVE-2021-32847

Affected software / configurations for CVE-2021-32847

Vendor Product Version Raw CPE
mobyproject hyperkit <= 0.20210107 cpe:2.3:a:mobyproject:hyperkit:*:*:*:*:*:*:*:*

References for CVE-2021-32847

cvelogic Threat Intelligence