Heap corruption via zero-sized phrase buffer
Published May 6, 2021 · Updated Aug 4, 2024
Heap out-of-bounds write in parse_fix_phrase in Exim before 4.94.2 allows local users to corrupt heap memory via -F ''. An empty originator name makes parse_fix_phrase allocate len*4 bytes, then set its cursor to buffer+1 and write a null byte past the zero-sized allocation. Any unprivileged local user who can execute the setuid-root Exim binary can trigger the write, but full root compromise was not demonstrated.
Summary
What happened
Heap out-of-bounds write in parse_fix_phrase in Exim before 4.94.2 allows local users to corrupt heap memory via -F ''. An empty originator name makes parse_fix_phrase allocate len*4 bytes, then set its cursor to buffer+1 and write a null byte past the zero-sized allocation. Any unprivileged local user who can execute the setuid-root Exim binary can trigger the write, but full root compromise was not demonstrated.
The record
- CVE
- CVE-2020-28016
- Published
- May 6, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1068
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- May 6, 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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Public exploit references
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Technologies
Your stack
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Your stack
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