What’s Vulnerable › Vulnerabilities

CVE-2021-27208

• Severity: medium (CVSS 6.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-03-15 · updated 2026-06-17
• Weakness: CWE-120

Description

When booting a Zync-7000 SOC device from nand flash memory, the nand driver in the ROM does not validate the inputs when reading in any parameters in the nand’s parameter page. IF a field read in from the parameter page is too large, this causes a buffer overflow that could lead to arbitrary code execution. Physical access and modification of the board assembly on which the Zynq-7000 SoC device mounted is needed to replace the original NAND flash memory with a NAND flash emulation device for this attack to be successful.

Affected products

• Xilinx Zynq-7000 Firmware: all versions
• Xilinx Zynq-7000S Firmware: all versions

References

• http://www.onfi.org/specifications
• https://www.xilinx.com/products/silicon-devices/soc/zynq-7000.html
• https://www.xilinx.com/support/answers/76201.html
• http://www.onfi.org/specifications
• https://www.xilinx.com/products/silicon-devices/soc/zynq-7000.html
• https://www.xilinx.com/support/answers/76201.html

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