CVE-2023-5633: Kernel: vmwgfx: reference count issue leads to use-after-free in surface handling

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-10-23 · updated 2026-06-17
Weakness: CWE-911

Description

The reference count changes made as part of the CVE-2023-33951 and CVE-2023-33952 fixes exposed a use-after-free flaw in the way memory objects were handled when they were being used to store a surface. When running inside a VMware guest with 3D acceleration enabled, a local, unprivileged user could potentially use this flaw to escalate their privileges.

Affected products

Linux kernel: from 6.1.13 before 6.1.75; from 6.2 before 6.5.8; 6.6-rc1, 6.6-rc2, 6.6-rc3, 6.6-rc4, 6.6-rc5, 6.6-rc6 — fixed in 6.1.75, 6.5.8
RedHat Codeready Linux Builder: 8.0, 9.0
RedHat Codeready Linux Builder Eus: 8.8, 9.2, 9.4
RedHat Codeready Linux Builder For Arm64: 8.0_aarch64, 9.0_aarch64
RedHat Codeready Linux Builder For Arm64 Eus: 8.8_aarch64, 9.2_aarch64, 9.4_aarch64
RedHat Codeready Linux Builder For Ibm Z Systems: 9.0_s390x
RedHat Codeready Linux Builder For Ibm Z Systems Eus: 9.2_s390x, 9.4_s390x
RedHat Codeready Linux Builder For Power Little Endian: 8.0_ppc64le, 9.0_ppc64le
RedHat Codeready Linux Builder For Power Little Endian Eus: 8.8_ppc64le, 9.2_ppc64le, 9.4_ppc64le
Red Hat Enterprise Linux: 8.0, 9.0
RedHat Enterprise Linux Eus: 8.8, 9.2, 9.4
RedHat Enterprise Linux For Arm 64: 8.0_aarch64, 9.0_aarch64
RedHat Enterprise Linux For Arm 64 Eus: 8.8_aarch64, 9.2_aarch64, 9.4_aarch64
RedHat Enterprise Linux For Ibm Z Systems: 8.0_s390x, 9.0_s390x
RedHat Enterprise Linux For Ibm Z Systems Eus: 8.8_s390x, 9.2_s390x, 9.4_s390x
RedHat Enterprise Linux For Power Little Endian: 8.0_ppc64le, 9.0_ppc64le
RedHat Enterprise Linux For Power Little Endian Eus: 9.2_ppc64le, 9.4_ppc64le
RedHat Enterprise Linux For Real Time: 8.0, 9.0
RedHat Enterprise Linux For Real Time For Nfv: 8.0, 9.0
RedHat Enterprise Linux Server Aus: 9.2, 9.4
RedHat Enterprise Linux Server For Power Little Endian Update Services For Sap Solutions: 8.8, 9.2_ppc64le
RedHat Enterprise Linux Server Tus: 8.8

How to fix

Upgrade to a fixed version: Linux kernel 6.1.75, 6.5.8. Check the vendor advisory for mitigations.

References

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