CVE-2021-20255

Severity: medium (CVSS 5.5 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: 2021-03-09 · updated 2026-06-17
Weakness: CWE-835

Description

A stack overflow via an infinite recursion vulnerability was found in the eepro100 i8255x device emulator of QEMU. This issue occurs while processing controller commands due to a DMA reentry issue. This flaw allows a guest user or process to consume CPU cycles or crash the QEMU process on the host, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

Affected products

Debian Linux: 9.0
QEMU: all versions

References

https://bugzilla.redhat.com/show_bug.cgi?id=1930646
https://lists.debian.org/debian-lts-announce/2021/04/msg00009.html
https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Feepro100_stackoverflow1
https://security.netapp.com/advisory/ntap-20210507-0003/
https://www.openwall.com/lists/oss-security/2021/02/25/1
https://bugzilla.redhat.com/show_bug.cgi?id=1930646
https://lists.debian.org/debian-lts-announce/2021/04/msg00009.html
https://ruhr-uni-bochum.sciebo.de/s/NNWP2GfwzYKeKwE?path=%2Feepro100_stackoverflow1
https://security.netapp.com/advisory/ntap-20210507-0003/
https://www.openwall.com/lists/oss-security/2021/02/25/1

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