CVE-2020-11087Network attack vector

Out-of-bounds read via unchecked NTLM flags

Published May 29, 2020 · Updated Aug 4, 2024

Out-of-bounds read in FreeRDP 2.0.0 and earlier allows remote authenticated users to read process memory via a truncated NTLM message. The ntlm_read_AuthenticateMessage function reads the four-byte NegotiateFlags field without first confirming that four bytes remain in the input stream. All clients and servers using NTLM authentication are exposed, but a subsequent validation check aborts processing with an error.

CVSS severity3.1
Low
EPSS probability1.43%
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

Out-of-bounds read in FreeRDP 2.0.0 and earlier allows remote authenticated users to read process memory via a truncated NTLM message. The ntlm_read_AuthenticateMessage function reads the four-byte NegotiateFlags field without first confirming that four bytes remain in the input stream. All clients and servers using NTLM authentication are exposed, but a subsequent validation check aborts processing with an error.

The record

CVE
CVE-2020-11087
Published
May 29, 2020
Updated
Aug 4, 2024
Vendor
FreeRDP
Product
FreeRDP
Classifications
CWE-125
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 29, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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=<= 2.0.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

FreeRDP · FreeRDPversion=<= 2.0.0

Published CVSS scores

5.5NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:P
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L
3.1GitHub, Inc.CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

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