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Fencer Intel
medium 6.8

CVE-2021-44850 json

On Xilinx Zynq-7000 SoC devices, physical modification of an SD boot image allows for a buffer overflow attack in the ROM.

published 4y ago modified 4mo ago also EUVD-2021-31653

cvss
6.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

On Xilinx Zynq-7000 SoC devices, physical modification of an SD boot image allows for a buffer overflow attack in the ROM. Because the Zynq-7000's boot image header is unencrypted and unauthenticated before use, an attacker can modify the boot header stored on an SD card so that a secure image appears to be unencrypted, and they will be able to modify the full range of register initialization values. Normally, these registers will be restricted when booting securely. Of importance to this attack are two registers that control the SD card's transfer type and transfer size. These registers could be modified a way that causes a buffer overflow in the ROM.

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Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 6.8 CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.6 AV:L/AC:L/Au:N/C:P/I:P/A:P

Classification

Weakness
  • CWE-345 Insufficient Verification of Data Authenticity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.