What is CVE-2017-4933?

CVE-2017-4933 is a high-severity vulnerability in Apple Mac OS X, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2017-12-20.

How severe is CVE-2017-4933?

High severity. CVSS v3 base score is 8.8 out of 10.

Is CVE-2017-4933 known to be exploited?

4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Buffer overflow in Apple Mac OS X

CVE-2017-4933

VMware ESXi (6.5 before ESXi650-201710401-BG), Workstation (12.x before 12.5.8), and Fusion (8.x before 8.5.9) contain a vulnerability that could allow an authenticated VNC session to cause a heap overflow via a specific set of VNC packets resulting in heap corruption. Successful exploitation of this issue could result in remote code execution in a virtual machine via the authenticated VNC session. Note: In order for exploitation to be possible in ESXi, VNC must be manually enabled in a virtual machine's .vmx configuration file. In addition, ESXi must be configured to allow VNC traffic through the built-in firewall.

Vulnerability class: Buffer Overflow

Published 2017-12-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.036 (89.2th percentile), scored 2026-10-20.

Low probability of exploitation in the next 30 days, but still tracked. 89th percentile — 89.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.036 · newest: 0.036 · change: 0.000

Affected products

Apple Mac OS X
VMware Esxi — versions 6.5 before ESXi650-201710401-BG, 6.5
VMware Fusion — versions 8.x before 8.5.9
VMware Workstation — versions 12.x before 12.5.8
VMware Workstation Pro — versions 14.0, 14.1.0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

Public proof-of-concept exploits

References

www.vmware.com/security/advisories/VMSA-2017-0021.html (Issue Tracking, Vendor Advisory)
www.securitytracker.com/id/1040025 (VDB Entry, Third Party Advisory, vdb-entry)
www.securitytracker.com/id/1040024 (VDB Entry, Third Party Advisory, vdb-entry)

Frequently asked questions

What is CVE-2017-4933?: CVE-2017-4933 is a high-severity vulnerability in Apple Mac OS X, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2017-12-20.
How severe is CVE-2017-4933?: High severity. CVSS v3 base score is 8.8 out of 10.
Is CVE-2017-4933 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.