CVE-2021-31424

Hypervisor code execution via unchecked buffer copy

Published Apr 29, 2021 · Updated Aug 3, 2024

Heap-based buffer overflow in Parallels Desktop 15.1.5-47309 allows local users in a guest to execute code in the hypervisor. Open Tools Gate copies user-supplied data into a fixed-length heap buffer without first validating its length. Low-privileged code execution in the target guest is required, after which successful exploitation crosses the guest boundary and gains hypervisor-context execution.

CVSS severity8.8
High
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in Parallels Desktop 15.1.5-47309 allows local users in a guest to execute code in the hypervisor. Open Tools Gate copies user-supplied data into a fixed-length heap buffer without first validating its length. Low-privileged code execution in the target guest is required, after which successful exploitation crosses the guest boundary and gains hypervisor-context execution.

The record

CVE
CVE-2021-31424
Published
Apr 29, 2021
Updated
Aug 3, 2024
Vendor
Parallels
Product
Parallels Desktop
Classifications
CWE-122, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 29, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=15.1.5-47309

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Parallels · Parallels Desktopversion=15.1.5-47309

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
4.6NIST NVDAV:L/AC:L/Au:N/C:P/I:P/A:P
8.8Zero Day InitiativeCVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-122Heap-based Buffer Overflow
T1068Exploitation for Privilege Escalation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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