PatchTheCVECVE-2021-27208: When booting a Zync-7000 SOC device from nand flash memory, the nand driver in the ROM does not validate the i
CVE-2021-27208 is a medium-severity flaw (CVSS 6.8) affecting zynq-7000s firmware, zynq-7000 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 6.8 (Medium) |
| Attack vector | Physical |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | None |
| EPSS exploit chance | 0.4% (top 67%) |
| CISA exploited list | No |
| Weakness | CWE-120 |
| Published | 2021-03-15 |
| Last modified | 2026-06-17 |
Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2021-27208?
zynq-7000s firmware: mitigate or apply the listed mitigation; zynq-7000 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2021-27208 being exploited?
CVE-2021-27208 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2021-27208 affect?
CVE-2021-27208 affects zynq-7000s firmware, zynq-7000 firmware. Severity is medium (CVSS 6.8). 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 c
How urgent is CVE-2021-27208?
Priority 32/100. No elevated risk signals yet.
Related CVEs
- CVE-2022-23822 MEDIUM 6.8 UPGRADE UPGRADE In this physical attack, an attacker may potentially exploit the Zynq-7000 SoC First Stage Boot Loader (FSBL)