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CVE-2019-5544

VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow

9.8 CRITICALActively exploited (CISA KEV)Used in ransomwareEPSS 97.3%
  1. Published6 Dec 2019
  2. Added to CISA KEV3 Nov 2021
  3. Remediation due3 May 2022
Actively exploited (CISA KEV)

VMware ESXi and Horizon Desktop as a Service (DaaS) OpenSLP contains a heap-based buffer overflow vulnerability that allows an attacker with network access to port 427 to overwrite the heap of the OpenSLP service to perform remote code execution.

Added to KEV: 3 Nov 2021Federal remediation due: 3 May 2022Used in ransomware

Description

OpenSLP as used in ESXi and the Horizon DaaS appliances has a heap overwrite issue. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.8.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Openslp≤ 2.0.0
VMware Horizon Daas≥ 8.0.0 < 9.0.0.0
Fedoraproject Fedora30 · 31
Redhat Enterprise Linux Desktop6.0 · 7.0
Redhat Enterprise Linux For Ibm Z Systems6.0_s390x · 7.0_s390x
Redhat Enterprise Linux For Ibm Z Systems Eus7.7_s390x
Redhat Enterprise Linux For Power Big Endian6.0_ppc64 · 7.0_ppc64
Redhat Enterprise Linux For Power Big Endian Eus7.7_ppc64
Redhat Enterprise Linux For Power Little Endian7.0_ppc64le
Redhat Enterprise Linux For Power Little Endian Eus7.7_ppc64le
Redhat Enterprise Linux Server6.0 · 7.0
Redhat Enterprise Linux Server Aus7.7
Redhat Enterprise Linux Server Eus7.7
Redhat Enterprise Linux Server Tus7.7
Redhat Enterprise Linux Workstation6.0 · 7.0
VMware Esxi6.0 · 6.5

Remediation

Fixed in
VMware Horizon Daas≥ 9.0.0.0

References

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Frequently asked

Is CVE-2019-5544 being actively exploited?

Yes. CVE-2019-5544 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, added 3 Nov 2021. It has been used in ransomware campaigns.

How severe is CVE-2019-5544?

CVE-2019-5544 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 97.3% probability of exploitation.

Which products are affected by CVE-2019-5544?

Affected products include Openslp, VMware Horizon Daas, Fedoraproject Fedora, Redhat Enterprise Linux Desktop, Redhat Enterprise Linux For Ibm Z Systems, and 11 more.

How do I fix CVE-2019-5544?

Upgrade affected software to a fixed version, for example VMware Horizon Daas 9.0.0.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2019-5544 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. Because it is on the CISA KEV list, Secuno flags any affected asset as top-priority automatically. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.