{"cve":"CVE-2021-27208","nvd":{"published":"2021-03-15T13:15:14.967","modified":"2026-06-17T03:44:28.000","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":6.8},"cwes":["CWE-120"],"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"],"products":["xilinx:zynq-7000_firmware","xilinx:zynq-7000s_firmware"],"source":"nvd","synced_at":"2026-10-19T21:15:50.279857260+00:00"},"epss":{"cve":"CVE-2021-27208","score":0.00393,"percentile":0.33504,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}