CVE-2021-41160Network attack vector

Client memory corruption via unchecked graphics rectangles

Published Oct 21, 2021 · Updated Nov 3, 2025

Out-of-bounds write in FreeRDP before 2.4.1 allows remote attackers controlling an RDP server to corrupt connected-client memory. GDI and SurfaceCommands accept zero-sized or out-of-range graphics rectangles, allocate no matching region, and then write through the resulting pointer. Exploitation requires a user to connect the client to a malicious server, which can corrupt client memory or crash the process.

CVSS severity8.8
High
EPSS probability1.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in FreeRDP before 2.4.1 allows remote attackers controlling an RDP server to corrupt connected-client memory. GDI and SurfaceCommands accept zero-sized or out-of-range graphics rectangles, allocate no matching region, and then write through the resulting pointer. Exploitation requires a user to connect the client to a malicious server, which can corrupt client memory or crash the process.

The record

CVE
CVE-2021-41160
Published
Oct 21, 2021
Updated
Nov 3, 2025
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 21, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record 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=< 2.4.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FreeRDP · FreeRDPversion=< 2.4.1

Published CVSS scores

8.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
5.3GitHub Security AdvisoriesCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:N/I:H/A:N

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

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

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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