Hypervisor-memory disclosure via stale PVNVRAM pointer
Published Jun 25, 2020 · Updated Aug 4, 2024
Use-after-free in PVNVRAM in VMware ESXi, Workstation 15.x, and Fusion 11.x allows local users in a guest VM to read hypervisor memory. PVNVRAM's variable-store write path can update or delete an existing variable without clearing last_search_value, so a later find-next request dereferences the freed variable. Exploitation requires guest access and additional conditions outside the attacker's control; the documented consequence is hypervisor-memory disclosure, not modification or service interruption.
Summary
What happened
Use-after-free in PVNVRAM in VMware ESXi, Workstation 15.x, and Fusion 11.x allows local users in a guest VM to read hypervisor memory. PVNVRAM's variable-store write path can update or delete an existing variable without clearing last_search_value, so a later find-next request dereferences the freed variable. Exploitation requires guest access and additional conditions outside the attacker's control; the documented consequence is hypervisor-memory disclosure, not modification or service interruption.
The record
- CVE
- CVE-2020-3963
- Published
- Jun 25, 2020
- Updated
- Aug 4, 2024
- Vendor
- VMware
- Product
- VMware Workstation
- Classifications
- CWE-416, T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 25, 2020CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=15.x before 15.5.2
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- ESXi PVNVRAM use-after-free trigger descriptionproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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