Timestamp-check bypass via endian truncation
Published Oct 22, 2021 · Updated Aug 4, 2024
Numeric truncation in OpenPOWER skiboot 2.6 firmware allows attackers to bypass secure-variable timestamp checks via crafted update data. The unpack_timestamp() function in libstb/secvar/backend/edk2-compat-process.c applies le32_to_cpu() to the 16-bit year field and stores the converted result in a uint16_t, discarding significant bits. Exploitation requires a secure-variable update with an attacker-controlled timestamp; the published record does not specify any further consequence of bypassing the ordering check.
Summary
What happened
Numeric truncation in OpenPOWER skiboot 2.6 firmware allows attackers to bypass secure-variable timestamp checks via crafted update data. The unpack_timestamp() function in libstb/secvar/backend/edk2-compat-process.c applies le32_to_cpu() to the 16-bit year field and stores the converted result in a uint16_t, discarding significant bits. Exploitation requires a secure-variable update with an attacker-controlled timestamp; the published record does not specify any further consequence of bypassing the ordering check.
The record
- CVE
- CVE-2021-36357
- Published
- Oct 22, 2021
- Updated
- Aug 4, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-681
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Oct 22, 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?
Affected products and versions are unavailable in this record.
Attacks
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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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