How severe is CVE-2021-27208?

CVE-2021-27208 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-27208 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-27208?

CVE-2021-27208 primarily affects Xilinx Zynq-7000s Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-27208?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-27208 published?

CVE-2021-27208 was published on 2021-03-15 and last updated on 2026-06-17.

CVE-2021-27208

CVE-2021-27208 is a medium-severity vulnerability in Xilinx Zynq-7000s Firmware with a CVSS 3.x base score of 6.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.

Key facts

Severity: Medium (CVSS 3.x base score 6.8)
CVSS v2: 4.6
EPSS exploit prediction: 0% (30th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-120
Affected product: Xilinx Zynq-7000s Firmware
Published: 2021-03-15
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-27208?: 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.
How severe is CVE-2021-27208?: CVE-2021-27208 has a CVSS 3.x base score of 6.8, rated medium severity. It is exploitable over physical access with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-27208 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-27208?: CVE-2021-27208 primarily affects Xilinx Zynq-7000s Firmware. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-27208?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-27208 published?: CVE-2021-27208 was published on 2021-03-15 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:o:xilinx:zynq-7000s_firmware:-:*:*:*:*:*:*:*
cpe:2.3:o:xilinx:zynq-7000_firmware:-:*:*:*:*:*:*:*

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