Heap corruption via overflowing malloc size addition
Published Apr 30, 2021 · Updated Aug 3, 2024
Heap buffer overflow in klibc before 2.0.9 allows attackers to corrupt heap memory via oversized allocation requests. The malloc implementation adds allocator overhead to the requested size without first rejecting values above PTRDIFF_MAX, so the addition can wrap and reserve a buffer smaller than the caller expects. Triggering the flaw requires a caller-controlled oversized allocation; Ubuntu notes that its initramfs use does not parse untrusted data.
Summary
What happened
Heap buffer overflow in klibc before 2.0.9 allows attackers to corrupt heap memory via oversized allocation requests. The malloc implementation adds allocator overhead to the requested size without first rejecting values above PTRDIFF_MAX, so the addition can wrap and reserve a buffer smaller than the caller expects. Triggering the flaw requires a caller-controlled oversized allocation; Ubuntu notes that its initramfs use does not parse untrusted data.
The record
- CVE
- CVE-2021-31873
- Published
- Apr 30, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 30, 2021CVE 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?
Affected products and versions are unavailable in this record.
Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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