CVE-2021-2279Network attack vector

Unauthenticated code execution via VRDP heap overflow

Published Apr 22, 2021 · Updated Sep 26, 2024

Heap-based buffer overflow in Oracle VM VirtualBox before 6.1.20 allows remote attackers to execute code through crafted RDP traffic. The VRDP service copies user-supplied drdynvc packet data into a heap buffer without first validating its declared length. Exploitation requires network reachability to an enabled VRDP server and no authentication, and successful code execution runs in the RDP service context.

CVSS severity8.1
High
EPSS probability3.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap-based buffer overflow in Oracle VM VirtualBox before 6.1.20 allows remote attackers to execute code through crafted RDP traffic. The VRDP service copies user-supplied drdynvc packet data into a heap buffer without first validating its declared length. Exploitation requires network reachability to an enabled VRDP server and no authentication, and successful code execution runs in the RDP service context.

The record

CVE
CVE-2021-2279
Published
Apr 22, 2021
Updated
Sep 26, 2024
Vendor
Oracle Corporation
Product
Oracle VM VirtualBox
Classifications
T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 26, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=unspecified <6.1.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Oracle Corporation · Oracle VM VirtualBoxversion=unspecified <6.1.20

Published CVSS scores

8.1Oracle CorporationCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

T1210Exploitation of Remote Services

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo