CVE-2020-11899: Treck TCP/IP stack Out-of-Bounds Read Vulnerability

Q: How do I fix CVE-2020-11899?

tcp\/ip: upgrade to 6.0.1.66; wyse 5050 all-in-one firmware: mitigate or apply the listed mitigation; wyse 7030 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2020-11899 being exploited?

Yes. CVE-2020-11899 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

Q: What does CVE-2020-11899 affect?

CVE-2020-11899 affects tcp\/ip, wyse 5050 all-in-one firmware, wyse 7030 firmware. Severity is medium (CVSS 5.4). The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

Q: How urgent is CVE-2020-11899?

Priority 73/100. EPSS top 3%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference

Patch now

MEDIUM 5.4EXPLOITEDUPGRADEMITIGATEMITIGATE

CVE-2020-11899 is a medium-severity flaw (CVSS 5.4) affecting tcp\/ip, wyse 5050 all-in-one firmware, wyse 7030 firmware, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

Why this priority

EPSS top 3%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.4 (Medium)
Attack vector	Adjacent network
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	18.4% (top 3%)
CISA exploited list	Yes, fix due 2022-03-17
Weakness	CWE-125
Published	2020-06-17
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: dell · treck

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2020-06-17 11:15 UTCPublished CVE record published
2022-03-03Exploited Added to the CISA Known Exploited Vulnerabilities list
2022-03-17Deadline CISA due date for US federal agencies to patch
2026-06-17 02:51 UTCUpdated Record last modified

treck tcp\/ip UPGRADE

Affected: < 6.0.1.66

Fixed in: 6.0.1.66

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy tcpip || rpm -q tcpip || tcpip --version

2. UPGRADE to 6.0.1.66 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade tcpip

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade tcpip

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

dell wyse 5050 all-in-one firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

dell wyse 7030 firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

dell wyse 5030 firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Exact fixes by distribution

A distro patch exists: prefer upgrading over downgrading.

Fedora 46 · keepalived · FIXED · 2.4.3-1.fc46 · FEDORA-2026-0c83a077d7 · source

sudo dnf upgrade --advisory=FEDORA-2026-0c83a077d7

Fedora ELN · dracut · FIXED · 111-5.eln159 · FEDORA-2026-982407d9e3 · source

sudo dnf upgrade --advisory=FEDORA-2026-982407d9e3

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

Write-up: tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-treck-ip-stack-JyBQ
Write-up: www.jsof-tech.com/ripple20/
Write-up: www.kb.cert.org/vuls/id/257161

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2020-11899?

tcp\/ip: upgrade to 6.0.1.66; wyse 5050 all-in-one firmware: mitigate or apply the listed mitigation; wyse 7030 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2020-11899 being exploited?

Yes. CVE-2020-11899 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2020-11899 affect?

CVE-2020-11899 affects tcp\/ip, wyse 5050 all-in-one firmware, wyse 7030 firmware. Severity is medium (CVSS 5.4). The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.

How urgent is CVE-2020-11899?

Priority 73/100. EPSS top 3%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference

Software pages

Dell vulnerabilities

Related CVEs

CVE-2020-25066 CRITICAL 10.0 UPGRADE A heap-based buffer overflow in the Treck HTTP Server component before 6.0.1.68 allows remote attackers to cau
CVE-2020-11914 MEDIUM 4.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has an ARP Out-of-bounds Read.
CVE-2020-11913 MEDIUM 5.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has an IPv6 Out-of-bounds Read.
CVE-2020-11912 MEDIUM 5.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has a TCP Out-of-bounds Read.
CVE-2020-11911 MEDIUM 5.3 UPGRADE The Treck TCP/IP stack before 6.0.1.66 has Improper ICMPv4 Access Control.

References

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