Local privilege escalation via driver out-of-bounds write
Published Oct 10, 2023 · Updated Jul 9, 2026
Out-of-bounds write in Macrium Reflect 8.1.7544 and earlier allows local users to execute code or escalate privileges. The psmounterex.sys IRP_MJ_READ handler lets a caller choose an allocation size and disk file, then copies the file into that allocation without checking its length. Low-privilege local access is required; an oversized file corrupts the kernel heap, enabling kernel-level code execution and complete system-integrity loss.
Summary
What happened
Out-of-bounds write in Macrium Reflect 8.1.7544 and earlier allows local users to execute code or escalate privileges. The psmounterex.sys IRP_MJ_READ handler lets a caller choose an allocation size and disk file, then copies the file into that allocation without checking its length. Low-privilege local access is required; an oversized file corrupts the kernel heap, enabling kernel-level code execution and complete system-integrity loss.
The record
- CVE
- CVE-2023-43896
- Published
- Oct 10, 2023
- Updated
- Jul 9, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-120, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Oct 10, 2023CVE publishedPublication date reported by the CVE source.
- Jul 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What is affected?
Affected products and versions are unavailable in this record.
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
- psmounterex.sys out-of-bounds write demonstrationproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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