Assembler crash via freed preprocessor error state
Published Jul 26, 2022 · Updated Aug 3, 2024
Use-after-free in Yasm 1.3.0's NASM preprocessor allows local users to crash the assembler by processing a crafted source file. pp_getline frees a 160-byte directive allocation before tokenise calls error, which reads eight bytes from the released region. Exploitation requires Yasm to process the attacker-controlled file; the demonstrated outcome is an AddressSanitizer abort and interruption of that assembler invocation.
Summary
What happened
Use-after-free in Yasm 1.3.0's NASM preprocessor allows local users to crash the assembler by processing a crafted source file. pp_getline frees a 160-byte directive allocation before tokenise calls error, which reads eight bytes from the released region. Exploitation requires Yasm to process the attacker-controlled file; the demonstrated outcome is an AddressSanitizer abort and interruption of that assembler invocation.
The record
- CVE
- CVE-2021-33468
- Published
- Jul 26, 2022
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-416, T1204.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jul 26, 2022CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
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Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
- Yasm error use-after-free proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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