CVE-2020-13396Public exploitNetwork attack vector

Memory disclosure via attacker-sized NTLM challenge copy

Published May 22, 2020 · Updated Aug 4, 2024

Out-of-bounds read in FreeRDP before 2.1.1 allows attackers to disclose process memory through a crafted NTLM challenge. The ntlm_read_ChallengeMessage function adds attacker-controlled TargetName.Len and TargetInfo.Len values to the copy length, then copies from the input stream without checking that length against the source buffer. The target must process attacker-supplied NTLM authentication data; the demonstrated consequence is memory disclosure rather than code execution.

CVSS severity7.1
High
EPSS probability2.34%
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 read in FreeRDP before 2.1.1 allows attackers to disclose process memory through a crafted NTLM challenge. The ntlm_read_ChallengeMessage function adds attacker-controlled TargetName.Len and TargetInfo.Len values to the copy length, then copies from the input stream without checking that length against the source buffer. The target must process attacker-supplied NTLM authentication data; the demonstrated consequence is memory disclosure rather than code execution.

The record

CVE
CVE-2020-13396
Published
May 22, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-125
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 22, 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

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:L
5.5NIST NVDAV:N/AC:L/Au:S/C:P/I:N/A:P

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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read

Public exploit references

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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