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CVE-2019-5544: VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow Vulnerability

CVE-2019-5544 is rated critical with a CVSS v3.1 base score of 9.8 and affects VMware VMware ESXi and Horizon DaaS, along with 13 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means exploitation in the wild has been observed.

Vulnerability 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.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-787: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

Affected products

  • VMware Horizon Daas: from 8.0.0 before 9.0.0.0
  • VMware ESXi: 6.0; 6.0 1; 6.0 1a; 6.0 1b; 6.0 2; 6.0 3; 6.0 3a; 6.0 600-201504401; 6.0 600-201505401; 6.0 600-201507101; 6.0 600-201507102; 6.0 600-201507401
  • Openslp: up to and including 2.0.0
  • Red Hat Enterprise Linux Desktop: 6.0; 7.0
  • Red Hat Enterprise Linux For IBM Z Systems: 6.0_s390x; 7.0_s390x
  • Red Hat Enterprise Linux For IBM Z Systems Eus: 7.7_s390x
  • Red Hat Enterprise Linux For Power Big Endian: 6.0_ppc64; 7.0_ppc64
  • Red Hat Enterprise Linux For Power Big Endian Eus: 7.7_ppc64
  • Red Hat Enterprise Linux For Power Little Endian: 7.0_ppc64le
  • Red Hat Enterprise Linux For Power Little Endian Eus: 7.7_ppc64le
  • Red Hat Enterprise Linux Server: 6.0; 7.0
  • Red Hat Enterprise Linux Server Aus: 7.7
  • Red Hat Enterprise Linux Server Eus: 7.7
  • Red Hat Enterprise Linux Server Tus: 7.7
  • Red Hat Enterprise Linux Workstation: 6.0; 7.0

References