Kernel-stack disclosure via uninitialized dirent padding
Published Mar 26, 2021 · Updated Aug 4, 2024
Information disclosure in FreeBSD allows local users to read three uninitialized kernel-stack bytes through msdosfs directory reads. The msdosfs VOP_READDIR implementation returns generic dirent records without zero-filling the d_pad0 and d_pad1 padding fields. Exploitation requires read access to a directory on a mounted affected filesystem; the disclosed bytes can contain sensitive kernel-stack data.
Summary
What happened
Information disclosure in FreeBSD allows local users to read three uninitialized kernel-stack bytes through msdosfs directory reads. The msdosfs VOP_READDIR implementation returns generic dirent records without zero-filling the d_pad0 and d_pad1 padding fields. Exploitation requires read access to a directory on a mounted affected filesystem; the disclosed bytes can contain sensitive kernel-stack data.
The record
- CVE
- CVE-2020-25579
- Published
- Mar 26, 2021
- Updated
- Aug 4, 2024
- Vendor
- The FreeBSD Project
- Product
- FreeBSD
- Classifications
- CWE-909, T1005
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Mar 26, 2021CVE publishedPublication date reported by the CVE source.
- Aug 4, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=FreeBSD 12.2-RELEASE before p3, 12.1-RELEASE before p13, 11.4-RELEASE before p7
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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