CVE-2020-11896Public exploitNetwork attack vector

Unauthenticated RCE via tunneled fragment heap overflow

Published Jun 17, 2020 · Updated Aug 4, 2024

Heap overflow in Treck TCP/IP before 6.0.1.66 allows remote attackers to execute code via tunneled, fragmented UDP packets. The tfIpIncomingPacket trimming path assigns the inner packet's total length to both fragment and chain lengths, leaving linked fragments inconsistent before tfCopyPacket copies them into an undersized heap buffer. Exploitation requires IP fragmentation, IP tunneling, an open UDP port, and a nonempty receive queue; successful corruption executes attacker-controlled code on the embedded device.

CVSS severity10.0
Critical
EPSS probability36.85%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap overflow in Treck TCP/IP before 6.0.1.66 allows remote attackers to execute code via tunneled, fragmented UDP packets. The tfIpIncomingPacket trimming path assigns the inner packet's total length to both fragment and chain lengths, leaving linked fragments inconsistent before tfCopyPacket copies them into an undersized heap buffer. Exploitation requires IP fragmentation, IP tunneling, an open UDP port, and a nonempty receive queue; successful corruption executes attacker-controlled code on the embedded device.

The record

CVE
CVE-2020-11896
Published
Jun 17, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-20, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 17, 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.3NVDAV:N/AC:M/Au:N/C:C/I:C/A:C
10.0NVDCVSS:3.1/AV:N/AC:L/PR:N/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.

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 exploitPublished

Weakness, pattern, technique

CWE-20Improper Input Validation
T1190Exploit Public-Facing Application

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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