CVE-2021-28038

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-03-05 · updated 2026-06-17
Weakness: CWE-770

Description

An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV. A certain part of the netback driver lacks necessary treatment of errors such as failed memory allocations (as a result of changes to the handling of grant mapping errors). A host OS denial of service may occur during misbehavior of a networking frontend driver. NOTE: this issue exists because of an incomplete fix for CVE-2021-26931.

Affected products

Debian Linux: 9.0
Linux kernel: from 2.6.39 before 4.4.260; from 4.5.0 before 4.9.260; from 4.10.0 before 4.14.224; from 4.15.0 before 4.19.179; from 4.20.0 before 5.4.103; from 5.10.0 before 5.10.21 — fixed in 4.14.224, 4.19.179, 4.4.260, 4.9.260, 5.10.21, 5.11.4
NetApp Cloud Backup: all versions
NetApp Solidfire Baseboard Management Controller Firmware: all versions

How to fix

Upgrade to a fixed version: Linux kernel 4.14.224, 4.19.179, 4.4.260, 4.9.260. Check the vendor advisory for mitigations.

References

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