Guest-to-host memory corruption via unchecked RTAS nargs
Published Jul 26, 2021 · Updated Aug 4, 2024
Out-of-bounds write in Linux kernel KVM through 5.13.5 allows guest OS users on PowerPC hosts to corrupt host memory via H_RTAS. kvmppc_rtas_hcall uses the guest-supplied nargs value without a range check to place rets outside its stack array, then writes the fixed failure value -3 through that pointer. A malicious KVM guest gets one corrupting write before termination, allowing a host crash or other host-memory corruption but not attacker-selected write data.
Summary
What happened
Out-of-bounds write in Linux kernel KVM through 5.13.5 allows guest OS users on PowerPC hosts to corrupt host memory via H_RTAS. kvmppc_rtas_hcall uses the guest-supplied nargs value without a range check to place rets outside its stack array, then writes the fixed failure value -3 through that pointer. A malicious KVM guest gets one corrupting write before termination, allowing a host crash or other host-memory corruption but not attacker-selected write data.
The record
- CVE
- CVE-2021-37576
- Published
- Jul 26, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1611
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jul 26, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Attacks
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Technologies
Your stack
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