Local file overwrite via symlink-following state files
Published Nov 3, 2023 · Updated Sep 12, 2024
Symlink following in swtpm before 0.4.2 and 0.5.x before 0.5.1 allows local users to overwrite arbitrary files. State and lockfile creation opens predictable temporary paths such as TMP2-00.permall for writing without preventing symbolic-link traversal, so a crafted link redirects writes to another file. Exploitation requires local access to the configured TPM state directory and can corrupt files writable with the swtpm process's privileges, enabling privilege escalation.
Summary
What happened
Symlink following in swtpm before 0.4.2 and 0.5.x before 0.5.1 allows local users to overwrite arbitrary files. State and lockfile creation opens predictable temporary paths such as TMP2-00.permall for writing without preventing symbolic-link traversal, so a crafted link redirects writes to another file. Exploitation requires local access to the configured TPM state directory and can corrupt files writable with the swtpm process's privileges, enabling privilege escalation.
The record
- CVE
- CVE-2020-28407
- Published
- Nov 3, 2023
- Updated
- Sep 12, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-59
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 3, 2023CVE publishedPublication date reported by the CVE source.
- Sep 12, 2024Record updatedLatest update available in the CVE record.
Exploitability
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