CVSS 8.8 · High EPSS 0,63%
Kerentanan Integer Overflow or Wraparound pada 7-zip. Skor CVSS 3.1 8.8 (High) menurut github.com.
7-Zip is a file archiver with a high compression ratio. Versions 26.00 and prior contain a heap buffer overflow vulnerability caused by an under-allocation in the NTFS compressed stream buffer (GetCuSize shift UB), potentially allowing attackers to cause arbitrary code execution or application crashes. CInStream::GetCuSize() in the NTFS handler computes the compression-unit buffer size as (UInt32)1 << (BlockSizeLog + CompressionUnit), and a crafted image with ClusterSizeLog >= 28 and CompressionUnit == 4 drives the exponent to 32, which is undefined behavior and collapses on x86/x64 so _inBuf is allocated as 1 byte. ReadStream_FALSE then writes up to 256 MB of attacker-controlled data into that 1-byte buffer in 64 KB iterations, and because the CInStream object sits only 304 bytes after _inBuf, its vtable pointer is overwritten and the next dispatched call achieves a vtable hijack. On 32-bit builds the overflow is unconditionally reached; on 64-bit it requires the parallel 8 GB _outBuf allocation to succeed, otherwise failing closed to denial of service. The NTFS handler is enabled by default in stock 7z.dll and, via signature-based fallback matching "NTFS " at offset 3, will open a crafted image regardless of file extension during extraction or testing. Version 26.01 fixes the issue.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
· uraikan di kalkulator | Vendor | Produk | Versi terdampak |
|---|---|---|
| 7-zip | 7-zip | Semua versi sebelum 26.01 |