Memory corruption via stale serialization buffer pointer
Published Feb 24, 2022 · Updated Aug 3, 2024
Use-after-free in SPICE usbredir before 0.11.0 allows local users to corrupt process memory during parser-state serialization. The serializer retains an absolute pointer to the write-buffer count slot while serialize_data can reallocate and free the 64 KB state buffer, then writes a 32-bit count through that stale pointer. Exploitation requires high local privileges, primed write buffers, a slow or blocked destination, and a narrow serialization window.
Summary
What happened
Use-after-free in SPICE usbredir before 0.11.0 allows local users to corrupt process memory during parser-state serialization. The serializer retains an absolute pointer to the write-buffer count slot while serialize_data can reallocate and free the 64 KB state buffer, then writes a 32-bit count through that stale pointer. Exploitation requires high local privileges, primed write buffers, a slow or blocked destination, and a narrow serialization window.
The record
- CVE
- CVE-2021-3700
- Published
- Feb 24, 2022
- Updated
- Aug 3, 2024
- Vendor
- SPICE
- Product
- usbredir
- Classifications
- CWE-416
- Attack vector
- local
- Privileges
- admin
Timeline
How it unfolded
- Feb 24, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 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?
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- Affected versionversion=usbredir 0.11.0
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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